Electra63 Posted January 22, 2023 Share Posted January 22, 2023 Thanks for the advice Jim! I'm pretty sure it's not electrical but I'll test it today as you suggest. If it's the valve sticking on can I verify that by checking for other symptoms like heat in the wheels generated by the dragging brakes or might it not be significant enough to notice? Link to comment Share on other sites More sharing options...
Electra63 Posted January 22, 2023 Share Posted January 22, 2023 Hi Jim. So I carried out your test on my driveway. When the engine was cold the lights stayed off. I pumped the brakes a few times and each time the lights went off and stayed off after the pedal was released. After 10-15 minutes when everything had warmed up the lights came on without the pedal being touched so I carried out your test. When the connector is pulled off the switch the brake lights do go out...and back on when I put the connector back. Then I pumped the pedal a couple of times and they went off. This time it took a few minutes but again they eventually came back on again. I read in the shop manual that there is an air filter on the back end. Do you think a blocked air filter could contribute to my symptoms i.e. not enough air can get into the back end of the booster to keep it from 'fading on'? Or is it certain to be an internal leak in the booster? By the way I took the opportunity to run a couple of tests from the shop manual including confirming that the vacuum boost is working ok by pumping the pedal until it went hard and then starting the engine with my foot on the pedal Thanks. Mark Link to comment Share on other sites More sharing options...
EmTee Posted January 22, 2023 Share Posted January 22, 2023 Could this simply be another bad pressure switch? It seems that others have had quality problems with these... Link to comment Share on other sites More sharing options...
Electra63 Posted January 22, 2023 Share Posted January 22, 2023 Thanks for the comment Emtee. This was my first thought after getting the car. I saw the seller had left the stop light connector off so I clipped it back on and then discovered the brake lights were on most of the time. I also had it intermittently not working same with the turn signals. Figured it was a ground fault. After cleaning and checking all the connections in the trunk to be sure it fixed the turn signals etc but the brake lights were still acting up so I got a replacement hydraulic switch from Rockauto. This was in August time . I figured for $10 it was worth a try. The brake lights then seemed to behave better but I'd not taken it for much of a drive. It spent most of the time in the garage but I would start it and let it idle a couple of times a week. I was disappointed to see it acting up again yesterday after taking it for a longer drive - about 20-30 minutes. It's definitely intermittent and less frequent than before I installed the new switch Not sure this extra detail helps at all? Link to comment Share on other sites More sharing options...
Electra63 Posted January 22, 2023 Share Posted January 22, 2023 (edited) could engine heat radiating onto the front of the booster and onto the master cylinder be a contributing factor? Edited January 22, 2023 by Electra63 (see edit history) Link to comment Share on other sites More sharing options...
EmTee Posted January 23, 2023 Share Posted January 23, 2023 11 minutes ago, Electra63 said: could engine heat radiating onto the front of the booster and onto the master cylinder be a contributing factor? Possibly. Are you sure the brakes are releasing completely at all wheels? I have found that checking wheel temperatures immediately following a drive using an IR thermometer can be very helpful. A sticking wheel cylinder or bad/collapsed hose can be detected by comparing wheel temperatures. I used temps to fine-tune the brake adjustments on my '67 Riviera. Link to comment Share on other sites More sharing options...
Electra63 Posted January 23, 2023 Share Posted January 23, 2023 47 minutes ago, EmTee said: Possibly. Are you sure the brakes are releasing completely at all wheels? I have found that checking wheel temperatures immediately following a drive using an IR thermometer can be very helpful. A sticking wheel cylinder or bad/collapsed hose can be detected by comparing wheel temperatures. I used temps to fine-tune the brake adjustments on my '67 Riviera. Thanks. Yes I did think about this following Jim's comment about being like driving with your foot resting on the brake I just drove it for about 20 minutes. Half way around I stopped and the front brake drums felt pretty hot whereas the rears were fairly cool. I had just been down a hill so on the return part of the circuit I tried to stay off the brakes as much as possible. When I arrived home the front drums seemed very hot - hotter than when I stopped part way and to the point that touching them for more than a couple of seconds would cause a burned finger. The rears still seemed fairly cool. Seems like the fronts could well be binding? The previous owner said he had the wheel bearings and all the brakes serviced/replaced, but that's not to say everything was perfect once the job was complete... Any tests or checks you can suggest to confirm if they are not releasing properly and/or where the problem could be ? thanks again ! Link to comment Share on other sites More sharing options...
EmTee Posted January 23, 2023 Share Posted January 23, 2023 The first thing I would do if I suspected a wheel not releasing would be to raise the wheel and try to spin the wheel while it's still hot. If it feels locked-up, or heavy drag, try opening the bleeder briefly then try turning the wheel. If that releases the drag, then the brake hose has likely collapsed internally and failed. If the wheel is still locked, then you should pull the drum and check for mechanical issues or a leak (oil or brake fluid) that has contaminated the shoes. Link to comment Share on other sites More sharing options...
RivNut Posted January 23, 2023 Share Posted January 23, 2023 Check your owners manual for removal of the front drums. Unlike most drums, the Buic drums are riveted to the hub, they come off as a unit. A guy here locally broke many fins using a jammer to try and remove the drums thinking they just slipped over the lugs. 1 Link to comment Share on other sites More sharing options...
Electra63 Posted January 23, 2023 Share Posted January 23, 2023 Thanks guys. I'm still in 'discovery mode' with this vehicle. I'll update once I've done more testing. I just got myself another task 😏 but glad to be zeroing in on the possible issue. Link to comment Share on other sites More sharing options...
telriv Posted January 23, 2023 Share Posted January 23, 2023 (edited) Loosen up the master cylinder hold down bolts 1 1/2 turns each, drive it to see IF the symtoms return. IF they don't then the pushrod is too far into the master & needs to be adjusted. Tom T. Edited January 23, 2023 by telriv (see edit history) 2 Link to comment Share on other sites More sharing options...
Chasander Posted January 23, 2023 Share Posted January 23, 2023 Are you using Silicone brake Fluid? I failed 3 brake switches, finally read the instructions that came with the switch. DO NOT use with Silicon brake fluid. Link to comment Share on other sites More sharing options...
Jim Cannon Posted January 23, 2023 Share Posted January 23, 2023 17 hours ago, Electra63 said: Hi Jim. So I carried out your test on my driveway. When the engine was cold the lights stayed off. I pumped the brakes a few times and each time the lights went off and stayed off after the pedal was released. After 10-15 minutes when everything had warmed up the lights came on without the pedal being touched so I carried out your test. When the connector is pulled off the switch the brake lights do go out...and back on when I put the connector back. Then I pumped the pedal a couple of times and they went off. This time it took a few minutes but again they eventually came back on again. I read in the shop manual that there is an air filter on the back end. Do you think a blocked air filter could contribute to my symptoms i.e. not enough air can get into the back end of the booster to keep it from 'fading on'? Or is it certain to be an internal leak in the booster? Thanks. Mark Mark- Call Booster Dewey and ask him. He is a real expert on these vacuum units. If it's not the filter causing it, he will know what the likely cause is. I suspect a dirty, stick valve that is not fully sealing and slowly letting engine vacuum build up and actuate the brakes again. You can describe to him the tests you have done and that will help him diagnose it. I suspect the booster needs to be disassembled, have a good clean, reseal and put back together. Booster Dewey can do this. 1 Link to comment Share on other sites More sharing options...
1965rivgs Posted January 23, 2023 Share Posted January 23, 2023 Mark, Make sure the brake pedal is returning to a "full up" position when at rest. This is a 10 second test which is easy to do as a starting point. I have encountered quite a few boosters which allow the brake pedal to drop toward the floor eliminating the free play between the booster and push rod. In the cases I have encountered, the vehicles had electric switch actuated brake lights but I would guess this is possible with a hydraulic situation also. In these circumstances the booster function was normal with the exception of a vacuum loss/hissing sound when the booster allowed the pedal to fall toward the floor. For frugal owners who didnt want to spend the $$$, I simply installed an under dash return spring to hold the pedal in the "full up" position. Having stated the above, in my experience as a fleet mechanic, we had quite a few old Ford light duty trucks with the hydraulic brake light switch. The switches were not very reliable and it was typical to need to replace them consistently. The symptom was always "brake lights stay on". It is very, very possible, in spite of the fact the switch is "new", it may be bad. Perhaps the "on" threshold in the switch is low enough so the residual pressure in the brake system, typically around 8 lbs., is activating the switch. Your observation regarding the front brake heat would lead me to believe pressure is building in the system...but if your rear brakes are adjusted properly you should be seeing the same symptom at the rear brakes. Typical reasons for building pressure in the system would be no freeplay between the rear of the master cylinder piston and the pushrod, or a collapsed, inner rubber brake line which allows fluid to travel toward the wheel but not back to the master, essentially creating a check valve in the brake line. But both front wheels? And building pressure only AFTER the brake system is idle for a period of time? I suspect some of your symptoms may be normal but have come under scrutiny with the brake light issue. Tom Mooney 2 Link to comment Share on other sites More sharing options...
Electra63 Posted January 23, 2023 Share Posted January 23, 2023 Thanks everyone. Plenty of food for thought here.... I'm going to work my way through the various suggestions including the pushrod too far in as mentioned by Tom T. This had occurred to me after spending some time reading the manual more in depth about the booster... All the various suggestions are valid so I'm going to put them into a 'to do' list with the quickest/cheapest at the top and work my way down. I'll feed back what I discover thanks again for all the input - you guys are awesome Link to comment Share on other sites More sharing options...
Electra63 Posted January 23, 2023 Share Posted January 23, 2023 6 hours ago, Chasander said: Are you using Silicone brake Fluid? I failed 3 brake switches, finally read the instructions that came with the switch. DO NOT use with Silicon brake fluid. thanks for the input. The previous owner had the work done on the brakes so I don't know what type of fluid was used. Is there an easy way to verify this if I bleed some out or take some from the master cylinder reservoir? Link to comment Share on other sites More sharing options...
Electra63 Posted January 23, 2023 Share Posted January 23, 2023 2 minutes ago, Electra63 said: thanks for the input. The previous owner had the work done on the brakes so I don't know what type of fluid was used. Is there an easy way to verify this if I bleed some out or take some from the master cylinder reservoir? oh.... I just found this.... Link to comment Share on other sites More sharing options...
Electra63 Posted January 24, 2023 Share Posted January 24, 2023 Update of todays tests. 1. Brake fluid is definitely glycol based, not silicone so looks like I'm good there. I used the test in the Youtube video - and there is also the slightly sweet aroma of glycol. 2. Jacked up front while car was cold and both front wheels rotated quite freely. Just a very slight rub (noise) on passenger side. 3. Started car and let it warm up with the front wheels still in the air. Waited 15-20 minutes with it idling until the brake lights 'magically' came on as expected. It seems like the whole engine bay has to get fairly warm before this happens. 4. Checked front wheels and there was a heavy drag. I could still turn the wheels by hand but it took quite a bit more effort than before. 5. Pumped the brakes, brake lights went out as usual and I then immediately tried to spin the front wheels again. No difference - the same amount of drag as in step 4. Like they hadn't fully released. 6. Checked the brake pedal. It seems to sit up in the air quite nicely but there is little to no free travel. As soon as I touch the pedal I can hear a hiss echoing from the vacuum tank under the fender and as I release the pedal I hear a sucking noise from under the dash. I assume this is normal. Let me know if not.... 7. Let the front down and jacked up the back axle (once the brake lights came on by themselves again). Wheels seemed free but difficult to tell due to the driveline/diff drag. 8. Stopped the engine and let the car sit for a while (30-40 minutes) to cool down. Then I pumped the brakes with engine still off to release the vacuum in the system/tank and checked the front wheels again. Very slightly less drag on both but they were still binding quite bad. Despite pumping the brakes quite a few times I could not get them to release much more at all and certainly not back to how they were spinning in #2. Does all this give any more clues? As I said it seems to be heat related but perhaps the heat is just bringing out the worst in the booster.... BUT the fact the wheels don't spin freely when the engine is off and the pedal pumped a few times seems to say otherwise. Note: I just had all the 3 brake hoses replaced last week. The symptoms are no different to before the brake hose replacement so I know it's not the hoses. By the way I still have drum brakes all around. No mods or upgrade (yet...I may switch the front to discs if its easy and parts are freely available for the mod... ) My 28-year-old son is a big gear head with his own car projects and recommends I take the wheels off and check that the drum brakes are operating freely and correctly adjusted before pulling the trigger on a booster rebuild. All thoughts/suggestions welcome at this point... next steps? thanks for reading ! Link to comment Share on other sites More sharing options...
Jim Cannon Posted January 24, 2023 Share Posted January 24, 2023 Your tests make sense. It's not just a faulty brake light switch if the drums seem to bind when the light is on. If you did not do the recent brake work, it would be a good idea to pull the front drums for a quick look. You might be surprised at what you find. I still suspect the booster. 1 Link to comment Share on other sites More sharing options...
Electra63 Posted January 24, 2023 Share Posted January 24, 2023 (edited) Thanks Jim. If the brake inspection reveals nothing I'll probably call Booster Dewey and talk to him as you suggested. By the way I think I have a Moraine booster. Am I right (see the pic I posted earlier)? Mark Edited January 24, 2023 by Electra63 (see edit history) Link to comment Share on other sites More sharing options...
1965rivgs Posted January 24, 2023 Share Posted January 24, 2023 14 hours ago, Electra63 said: Update of todays tests. 1. Brake fluid is definitely glycol based, not silicone so looks like I'm good there. I used the test in the Youtube video - and there is also the slightly sweet aroma of glycol. 2. Jacked up front while car was cold and both front wheels rotated quite freely. Just a very slight rub (noise) on passenger side. 3. Started car and let it warm up with the front wheels still in the air. Waited 15-20 minutes with it idling until the brake lights 'magically' came on as expected. It seems like the whole engine bay has to get fairly warm before this happens. 4. Checked front wheels and there was a heavy drag. I could still turn the wheels by hand but it took quite a bit more effort than before. 5. Pumped the brakes, brake lights went out as usual and I then immediately tried to spin the front wheels again. No difference - the same amount of drag as in step 4. Like they hadn't fully released. 6. Checked the brake pedal. It seems to sit up in the air quite nicely but there is little to no free travel. As soon as I touch the pedal I can hear a hiss echoing from the vacuum tank under the fender and as I release the pedal I hear a sucking noise from under the dash. I assume this is normal. Let me know if not.... 7. Let the front down and jacked up the back axle (once the brake lights came on by themselves again). Wheels seemed free but difficult to tell due to the driveline/diff drag. 8. Stopped the engine and let the car sit for a while (30-40 minutes) to cool down. Then I pumped the brakes with engine still off to release the vacuum in the system/tank and checked the front wheels again. Very slightly less drag on both but they were still binding quite bad. Despite pumping the brakes quite a few times I could not get them to release much more at all and certainly not back to how they were spinning in #2. Does all this give any more clues? As I said it seems to be heat related but perhaps the heat is just bringing out the worst in the booster.... BUT the fact the wheels don't spin freely when the engine is off and the pedal pumped a few times seems to say otherwise. Note: I just had all the 3 brake hoses replaced last week. The symptoms are no different to before the brake hose replacement so I know it's not the hoses. By the way I still have drum brakes all around. No mods or upgrade (yet...I may switch the front to discs if its easy and parts are freely available for the mod... ) My 28-year-old son is a big gear head with his own car projects and recommends I take the wheels off and check that the drum brakes are operating freely and correctly adjusted before pulling the trigger on a booster rebuild. All thoughts/suggestions welcome at this point... next steps? thanks for reading ! The suggestion that you should visually inspect the brakes is a good one. You might also want to fine tune your troubleshooting by isolating the pressure build up to either 1) the engine running with no brake pedal application which involves the booster and/or thermal considerations but not foot pedal brake application; and 2) a second test without the engine running but with repeated foot pedal brake applications which negates booster involvement. The first test will only involve the possibility that the booster is applying brake system pressure and the pressure buildup is not due to foot pedal application. The second test without engine running and therefore no vacuum to the booster will determine if there is a component issue other than the booster by only applying the components of the system via foot pedal application absent the booster/thermal considerations. Your issue is interesting as I have never encountered a bad booster which applies brake pedal pressure. Good luck! Tom Mooney 1 Link to comment Share on other sites More sharing options...
Electra63 Posted January 24, 2023 Share Posted January 24, 2023 Thanks Tom. I like this suggestion. Link to comment Share on other sites More sharing options...
Electra63 Posted March 19, 2023 Share Posted March 19, 2023 (edited) Hello again, guys I thought I'd post a quick update. After some deliberations I decided to follow Tom T's advice of backing off the nuts holding the master cylinder onto the booster to see if the problem could be coming from the booster pin being too far out and pressing lightly onto the master cylinder when the brake pedal was not depressed. I even bought the original gage from ebay in anticipation. I was amazed they can still be found for sale. I loosened the nuts and progressively moved it back but I got the same symptoms - brake lights coming on for no reason. This was despite loosening the nuts quite a bit and pulling the master cylinder away from the booster. So I tightened everything back up. I had also spent time scouring the shop manual and this sentence from paragraph 9-15 d) gave me hope that I could avoid rebuild of the booster: "Many brake troubles which are blamed on the power brake unit may actually be caused by a defect outside of this unit" After scratching my head some more I decided to do the cheapest/easiest thing first and - thinking about another comment that the brake light hydraulic switch could be bad even though I'd recently replaced it - I decided to drop $15 on a(nother) replacement of a different brand. So today I swapped them out. I had the car in Park but as I unscrewed the old brake light switch to remove it and a little fluid dripped out, I felt the brakes release and the car moved slightly. Evidently some pressure was trapped in the front end of the master cylinder and holding the brakes on. After installing the new switch and warming up the car, the lights didn't come on as they had done before. So I pressed the brakes quite a few times and then waited to see what would happen and hey-ho the brake lights stayed off. After multiple more attempts to get the same symptoms to return I could not. I'm now suspecting something internal to the master cylinder like a sticking piston or compensating port blocked by dirt etc. I saw on another thread a comment that sometimes when bleeding the brakes, pressing the pedal to the floor can push the piston into areas it had not been previously been moving and causing sticking or seal damage. Its possible this happened when the local shop replaced the brake hoses for me and bled the system. Anyway I'm hoping that now what seemed to be residual trapped pressure in the front end of the cylinder/light switch has been released perhaps it was enough to solve/release the problem. Either way I now do believe its related to the master cylinder and not the booster. I'm always open minded so If anyone has another opinion let me know thanks for reading Mark Edited March 19, 2023 by Electra63 (see edit history) 1 Link to comment Share on other sites More sharing options...
Electra63 Posted March 28, 2023 Share Posted March 28, 2023 A final update. After three more trips in the vehicle I'm now convinced it was the master cylinder. The brake light symptoms have not come back and the brakes are not binding. My theory is that when I had my local shop replace the brake hoses and they bled the system, they pumped the pedal hard, beyond its usual stroke, and something in the master cylinder got hung up or dirt got stuck in an internal port or check valve. This held/trapped some pressure in the front end of the master cylinder that caused the brakes to bind. Since the pressure was trapped, when the engine bay heated up and the fluid expanded slightly, with nowhere to go, the pressure increased enough to actuate the hydraulic brake light switch causing the brake lights to come on. It was Tom Mooney's post linked below that gave me hope. His post offers a clear description of the cause : I'm pleased to say that my booster seems to be OK so that saved me some $$ that I can spend on other restoration jobs ! Thanks again to everyone who took the time to share their advice. Mark Link to comment Share on other sites More sharing options...
Electra63 Posted April 22, 2023 Share Posted April 22, 2023 A quick supplemental comment.... Concerning the pushrod distance into the master cylinder, the factory manual references gauge Tool #J-21183 If you google this there are a couple for sale on ebay at the time of writing. I was surprised to see 3 or 4 on offer so I purchased one The real question (not given in the manual) is: what is the distance measurement (i.e. the inside measurement) of the gauge Well in case anyone needs it and can't get hold of a gauge, the measurement on my gauge is 1-7/32" or 31mm Mark Link to comment Share on other sites More sharing options...
OldGerman Posted April 23, 2023 Share Posted April 23, 2023 Killed my Single MC during bench bleeding by applying to much stroke. The inner seal traveld beyond a bore and the fluid dripped out in the rear. I measured the stroke of the push rod when brake pedal is pushed to floor. It was only about 1“ of stroke, which surprised me. For the next Time bench bleeding, I‘ve added a restriction, to prevent to much stroke. I have also Build my own tool to measure piston depth and to adjust pushrod length. 1 Link to comment Share on other sites More sharing options...
Electra63 Posted June 2, 2023 Share Posted June 2, 2023 Ok so I'm back again! My brakes seemed to be fine for a while but earlier this week the issue returned. Disappointed, I decided it was time to replace the master cylinder as the cost was less than $60 Sooo once the new unit arrived I removed the existing master cylinder This was the first time digging into the brake system since I bought the car. Once I removed the existing cylinder and emptied it out this is what I found. See pics Quite surprising since : 1. The last owner had the brakes serviced and all brake shoes etc replaced. I can see the new parts clearly. 2. I paid a local shop to replace the brake hoses which were still original and they obviously had to flush or at least bleed the system ! No wonder pressure was being trapped in the master cylinder and causing the brakes not to fully release. I'll be replacing the cylinder and flushing the heck out of the whole system. Just goes to show that you've got to understand and care about the condition of your own vehicle as repair shops often do only what you ask and nothing more...! 1 Link to comment Share on other sites More sharing options...
EmTee Posted June 2, 2023 Share Posted June 2, 2023 As the saying goes: "If you want something done right..." 1 Link to comment Share on other sites More sharing options...
XframeFX Posted June 3, 2023 Share Posted June 3, 2023 Might as well replace that brake light switch while you're at it. 2 Link to comment Share on other sites More sharing options...
TexRiv_63 Posted June 3, 2023 Share Posted June 3, 2023 If you have that much rust in the master I hope you have rebuilt / replaced all the wheel cylinders. 1 Link to comment Share on other sites More sharing options...
Electra63 Posted June 4, 2023 Share Posted June 4, 2023 (edited) 8 hours ago, TexRiv_63 said: If you have that much rust in the master I hope you have rebuilt / replaced all the wheel cylinders. Thanks TexRiv. My brain hadn't gone that far yet as I'm focused on flushing all that gunk out of the lines but you're right. Sigh. Better safe than sorry...it is the brakes after all ... so I've just ordered a set of new wheel cylinders. One day soon I hope to be able to drive this thing around like a regular person without a care in the world. Ha ha... Eye roll Edited June 4, 2023 by Electra63 (see edit history) 1 Link to comment Share on other sites More sharing options...
TexRiv_63 Posted June 4, 2023 Share Posted June 4, 2023 12 hours ago, Electra63 said: Thanks TexRiv. My brain hadn't gone that far yet as I'm focused on flushing all that gunk out of the lines but you're right. Sigh. Better safe than sorry...it is the brakes after all ... so I've just ordered a set of new wheel cylinders. One day soon I hope to be able to drive this thing around like a regular person without a care in the world. Ha ha... Eye roll Good job. Unfortunately just about any old car that hasn't been maintained or has set for a long time almost automatically needs the brake hydraulics rebuilt completely. Link to comment Share on other sites More sharing options...
Electra63 Posted June 4, 2023 Share Posted June 4, 2023 2 hours ago, TexRiv_63 said: Good job. Unfortunately just about any old car that hasn't been maintained or has set for a long time almost automatically needs the brake hydraulics rebuilt completely. Thanks....yes understood. I was quite shocked to see the condition of the master cylinder once I tipped out the fluid, as the previous owner assured me he had the brake system fully replaced/serviced. He had been driving it for over a year. I guess whoever did the brake job for him simply replaced the brake shoes (I can see that they are new) and IF they flushed the system they did a very poor/lazy job....other work he had done like fitting electronic ignition has been done to a much better standard, Anyway soon I'll have a completely restored brake system so worth the effort and peace of mind 1 Link to comment Share on other sites More sharing options...
Electra63 Posted June 5, 2023 Share Posted June 5, 2023 So while replacing the rear wheel cylinders one of the hard lines cracked. It was badly kinked and probably cracked as soon as I moved it and now it needs to be replaced obviously. It's 20" long and runs from the tee where the hose joins for the back axle to the rear left wheel cylinder The nut has a 3/8 hex and the line is 5/16 inverted flare So I run to AutoZone to get this tube that looks like exactly what is need and states 3/8-24 thread. Everything looks perfect but when I compare the threads the pitch seems to be different and it won't screw into the wheel cylinder more than 1/2 turn. Ugh. https://www.autozone.com/brakes-and-traction-control/brake-line/p/ags-nicopp-3-16in-x-20in-nickel-copper-brake-line/97802_0_0 Can anyone tell me what the thread size and pitch is on those flare nuts on the 5/16 hard lines and/or where to get one ? I also found a pair of lines for the rear axle of a 63 Chevy Impala for sale in driving distance from me that might work ? Perhaps? Anyone know if they are the same ? Thanks ! Link to comment Share on other sites More sharing options...
Electra63 Posted June 5, 2023 Share Posted June 5, 2023 PS: I just checked and the 59-64 Chevy Impala has the same rear wheel cylinders as the 63 big body Buicks.... fingers crossed...I'm going to call the vendor Link to comment Share on other sites More sharing options...
Electra63 Posted June 6, 2023 Share Posted June 6, 2023 So I discovered two things today 1. AutoZone gave me the wrong part -not the one I ordered so probably the one I pasted the link would have worked. The one they gave me was almost identical but had metric threads. 2. I drove to Classic Industries in Huntington Beach CA and this set for a Chevy Impala fits. Hope this helps someone later. https://www.classicindustries.com/product/all-years/chevrolet/elcamino/parts/BRA5901.html The left side went in fairly easily as bent from the factory. The right side needed some bending to get it around the diff 1 Link to comment Share on other sites More sharing options...
Electra63 Posted June 6, 2023 Share Posted June 6, 2023 (edited) On 4/23/2023 at 10:41 AM, OldGerman said: Killed my Single MC during bench bleeding by applying to much stroke. The inner seal traveld beyond a bore and the fluid dripped out in the rear. I measured the stroke of the push rod when brake pedal is pushed to floor. It was only about 1“ of stroke, which surprised me. For the next Time bench bleeding, I‘ve added a restriction, to prevent to much stroke. I have also Build my own tool to measure piston depth and to adjust pushrod length. By the way. When I received my new single MC from the supplier there was a red 'Warning' notice in the bag saying do not bench bleed this cylinder. Only bleed it in the vehicle due to the possibility of stroking it too far. So I installed mine and bled it (carefully) on the vehicle by not pressing the pedal down too far. I think that may be probably safer - for the single style at least... Edited June 6, 2023 by Electra63 (see edit history) Link to comment Share on other sites More sharing options...
EmTee Posted June 6, 2023 Share Posted June 6, 2023 I place a small 2x4 block under the brake pedal before I bleed brakes in order to limit the travel and not drive the piston further than it would normally operate. Otherwise, it's possible to push accumulated crud downstream into the brake system. 1 Link to comment Share on other sites More sharing options...
1965rivgs Posted June 6, 2023 Share Posted June 6, 2023 5 hours ago, Electra63 said: By the way. When I received my new single MC from the supplier there was a red 'Warning' notice in the bag saying do not bench bleed this cylinder. Only bleed it in the vehicle due to the possibility of stroking it too far. So I installed mine and bled it (carefully) on the vehicle by not pressing the pedal down too far. I think that may be probably safer - for the single style at least... I gravity bleed and never touch the brake pedal in most cases. Tom Mooney 1 Link to comment Share on other sites More sharing options...
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