How do I remove brake booster assembly on a 57? Help!

lancemb · April 17th, 2009

I am sure some of you long time experts have removed the master/booster assembly and have already either learned from trials and tribulations or perhaps I am missing something here?

I tried with no success to remove the large nut under the dash that holds the booster on - There is no room! The chassis manual calls for use of wrench 6618 - whatever that is! As best as I can tell it is about a 1-3/4" nut, but no standard wrench that large would ever fit in there!

Does anybody know where I can get a wrench to take this nut off? Thanks!

40series · April 18th, 2009

Hi Lance,

That nut has to come off. No other way. I did a 58 a few years back and literally had to make a wrench by grinding the outer radius of the head.

imported_Pete Phillips · April 18th, 2009

I think I used a big channel-lock pliers to get that off when I had my '58. It is not easy, but can be done. You do not need to have the factory wrench.
Pete Phillips
Sherman, Texas

lancemb · April 18th, 2009

I tried channel locks but by the time I got them up there there was no room to move them. I also thought of making my own as 40series suggested but was convinced there was a better way.

I consulted a 58 expert I know and he said what he has always done is use a long chisel and a heavy hammer to break it loose, after which it comes off easily. So, I went and equipped myself with said tools but haven't had time to sork on it again now. I'll report back with results. In the meantime if anyone has that wrench, I'd love to try that instead!

40series · April 18th, 2009

That works but you have a 50/50 chance off damaging the nut

sean1997 · April 19th, 2009

Not sure if this helps any, but I have a "Kent-Moore 1957 Buick Essential Service Tools" brochure. It has a picture of tool 6618. I've attached it so you can see what it looks like. It looks like you disconnect the push rod and then slip the wrench over it.

Smartin · April 19th, 2009

If the dash is completely removed, is it easier to get to?

imported_buick5563 · April 19th, 2009

That looks a lot like a modern plumbing wrench that you remove shower valves with. Might check your local hardware store's plumbing section.

lancemb · April 20th, 2009

Wow, thanks for the illustration Sean!

Mike, do you know what size shower valves are?

*Does anyone know for sure what size this nut is?

imported_buick5563 · April 20th, 2009

Lance,
I think I have seen them as a "kit" with five of the socket looking things and a straight "wrench". Maybe 7/8" to 1 1/2"???? If you need a LOT of torque, it may not work. Just when I saw the pic, that's what it reminded me of.

57Roadmaster75 · April 25th, 2009

Not a fun job. I cursed every 57 Buick engineer that day. Channel locks worked for me. Let me know if you still need to know what size the nut is. I replaced my booster a while back and the replacement came with a new nut. So I still have the old booster and nut at my shop.

lancemb · April 27th, 2009

I finally got the nut off using the chisel/hammer method in about 15 minutes and it is 1-3/4". There are a few burrs I need to clean up but the nut will still be fine. However, I think I am gong to try and recreate the dealer wrench for reassembly and future use. I know I will have to do this again at least once as I want to rebuild the other one!

Smartin · October 24th, 2009

Even with the dash off my 58, I am having no luck getting this nut off. I am going out to the garage to try the hammer/chisel method. I even had a big pair of channel locks on it, but there is a bracket sandwiched in there that doesn't allow a full grip with the big channel locks. GRRRRRRRRRRRR

Smartin · October 24th, 2009

I had to cut half of the nut off with a 3" grinder and then knock the other half off. It was really rusted on. I had to wrestle the booster out for about 20 minutes after I got the nut off!

I do believe this might be the hardest fight I've ever had just to get one nut loose.

d2_willys · October 27th, 2009

Can't u just use a 1 3/4 socket? I haven't been under my 58 dash yet, but will soon as I have to replace the left wiper assembly, and probably take the speedo assy out. Perhaps I can wish these parts out and back in? LMAO!

PS: Should be able to find the KM tool on EBAY, in the next few 100 years!

Smartin · October 27th, 2009

I wish..

The brake booster rod sticks out of the hole about a foot, and won't allow a socket to go over it.

The wiper assembly might not be too bad. It is just under the upper dash. The speedometer/instrument cluster is a bit of a bear. I believe you have to remove the water temp sender from the drivers side head and fish it back through the firewall, since it is permanently attached to the temp gauge. The oil pressure sender is removable from the back of the speedo cluster. There are a thousand wires and bulbs that plug into the back of it.

d2_willys · October 28th, 2009

Quote:

Originally Posted by Smartin

I wish..

The brake booster rod sticks out of the hole about a foot, and won't allow a socket to go over it.

The wiper assembly might not be too bad. It is just under the upper dash. The speedometer/instrument cluster is a bit of a bear. I believe you have to remove the water temp sender from the drivers side head and fish it back through the firewall, since it is permanently attached to the temp gauge. The oil pressure sender is removable from the back of the speedo cluster. There are a thousand wires and bulbs that plug into the back of it.

Thanks for the info on the speedo and wiper assembly access. My work is cut out for me! As far as the brake booster, well there may be some weird wrench at some of the hardware and farm impliment stores. I am going to take a gander, perhaps at lunch today.

Hey, I just noticed that u r in St. Charles, MO. My wife and I stayed there earlier this year while driving the 58 out from Ohio. Next time I go through there I would like to stop and see the limited. (PM me with your info)

You have the variable pitch dynaflow (PNDLR) in it, right? Mine has the original Flight pitch dynaflow (PRNDG) and is still going strong. Still keep on thinking it will shift, but then I remember how it works.

Smartin · October 28th, 2009

Yes, mine is not a flight pitch. PNDLR it is!

I'll PM you with my info.

trp3141592 · October 29th, 2009

Hi,

I have seen similarly formed-steel thin-wall sockets used for hub retaining nuts on axles. The steel sockets are called "Locknut sockets." A Google search for found Axle Nut Sockets and http://www.nextag.com/locknut-wrench/shop-html which show thin wall sockets in various sizes. I don't know what size you need, but maybe this is a good start for you.

--Tom

capgage · November 14th, 2009

Guys, this is a tough situation but not undoable, I've done it several times...

* No matter what, you have to unbolt the brackets for the brake pedal from the firewall. Probably even if you have the KM tool. * Take the entire brake pedal assembly off. There are a couple more bolts than the firewall ones, but they are obvious when you look at it.

Go get a 1-3/4" socket from Sears. Grind either hex or oct flats on the small end.

Now, you WILL have to remove the yoke, by loosening the jam nut, from the shaft. Not hard to do though. Once this is off, you can slip the socket onto the shaft and hopefully get enough leverage to get the nut off. You should.

Either use vise grips, channel locks, or for a really slick way - if you ground hex flats, you may be able to slip a long impact socket from HF onto there and clear the end of the shaft to get it off with true leverage from a socket wrench, using the right adapters. You can stack sockets this way for extra depth. Some eyeball bench grinding required, but it's easier than you think.

I have made many tools like this using Harbor Freight impact sockets which are very cheap compared to Sears. In fact, use one of the HF 1-3/4" impact sockets instead of Sears.

I prefer to do this in a situation where the dash is off. But it doesn't have to be. It just turns it into an upside-down operation if the dash is not off.

Mark

gearhead · December 18th, 2009

Hmm, I wonder if a wrench for removing water heater electrical elements would work. That is about 1 1/2 inch. They make those in sheet metal like the picture of the GM shows. I bought a socket that size to get out a really stubborn heater element.

I am taking apart my 57 Super parts car and I'll have to face this task soon. I'll be interested to hear how this all comes out.

simplyconnected · December 18th, 2009

Do '57 Chevy's with treadle-vac have the same nut? (sorry for going off subject). - Dave

SupRiv56R · June 6th, 2011

Hello to all. I have been read-only the forums on this site for a long time and decided to join to pay you all back for the tips and info I have received here by providing some info myself on this subject.

I just went through the power booster replacement on my '57 and provided the mechanic who was doing the work with all the various tips and methods of dealing with the large nut and its removal. I picked up the car last week and asked him how it went with the removal of that nut. He said it went fine. Their solution was to remove the pedal linkage and disconnect the shaft/rod then remove the nuts from the air housing under the hood. With that done and the brake line and vacuum pipes also removed, he was able to grab the booster/MC turn the entire unit to loosen the big nut. Once loose, he reached up under the dash and removed it the rest of the way. That what 30 years wrenching cars will do for you! A very elegant solution!

--Chris
1957 Buick Super Riviera 2DR
46,000 true miles
Owned since 1975

Smartin · June 6th, 2011

I tried doing that, and it still wouldn't spin, even with the nut removed. It was that badly rusted in the hole.

buick man · June 8th, 2011

Chris: How was he able to turn the booster/mc and loosen the big nut inside by doing that - did he have a wrench or socket on it from the inside before turning the booster/mc by hand? I would not think you could get that much leverage by just grabbing the booster/mc and giving it a spin. This guy must be a gorilla or he used a pry bar against it maybe?