1963 Riviera conversion to dual master cylinder with drum-drum questions

[SwedeDownUnderR63]

I have gone through most of the forum in regards to the conversion to dual master cylinder for my 1963 Riviera, still with drum/drum, (especially the appends by Jim Cannon) but run into an issue that I didn’t expected.

The old MC was replaced in 1998 (according to the service records that I have) with a Raybestos MC36134. I can’t find that they did anything else so I assume that this was a perfect match to the previously MC, it also seems to be one of the MC to be used on both a 63 and a 65 today according to rockauto.com.

 

I have measured the deep of the old MC and it is either 40 or 42mm (roughly 1 37/64” and 1 21/32”, I guess one should translate more to 1 9/16” and 1 11/16”) the different sizes is depending on if one measure in the exact bottom or on the side of the hole, the end of the piston (see picture). Should have measured before I bought the new MC…

 

I have also measured the deep dimple for the new MC that I sourced from Tony Gentilcore (the MC is for an Australian car but he has used the same on his 1965 Riviera):

15 or 20mm (19/32” and 25/32” which I guess is more to be 5/8” and ~¾”).

 

I understand that the MCs are different with a different length but I am confused in regards to what Jim Cannon mentioned in http://forums.aaca.org/topic/221099-63-riviera-dual-master-conversion-help/?hl=%2Bmaster+%2Bcylinder+%2Bconversion#entry1145797 where he talked about “either a (roughly) 1" deep hole or a 1/4" deep dimple” both numbers not even close to the measurements that I have (although that of course depends on the roughly part from human memory).

 

There is an adjusting screw for the push rod (see p9-27 in the Chassis service manual) that one potentially could use to adjust but the difference between the old and new is too large (20 mm or ¾”).

 

I need to source another MC as I understand it and I will see if Tony can assist. Maybe I was sent the wrong one. Does anyone have any better suggestions or comments? 

[SwedeDownUnderR63]

OK, some further research revealed that 1-5/8" seems to be the depth (also called Deep Piston Hole on rockauto.com) for my original MC. I will order a -67 Riviera MC for drum/drum with the Deep Piston Hole (which is what the one in the ROA conversion article talks about) unless there is an Australian alternative.

Learning...

[Seafoam65]

                If your booster has a push rod that pulls out the front of the booster and you can remove it, the easy solution

is to use a bench grinder to shorten it and use the master cylinder that you currently have. We have to do this all the time in my

shop when adding power brakes to a manual drum brake car. The boosters that people sell rarely have a push rod that is short enough. I had to do this on a 69 firebird power brake conversion a couple of weeks ago.

Edited January 26, 2016 by Seafoam65 (see edit history)

[SwedeDownUnderR63]

                If your booster has a push rod that pulls out the front of the booster and you can remove it, the easy solution

is to use a bench grinder to shorten it and use the master cylinder that you currently have. We have to do this all the time in my

shop when adding power brakes to a manual drum brake car. The boosters that people sell rarely have a push rod that is short enough. I had to do this on a 69 firebird power brake conversion a couple of weeks ago.

Hi Winston,

 

Thanks, that would have been an alternative but I prefer to keep it reversible as much as possible.

Tony Gentilcore told me that I was sent the wrong MC and that a replacement is on its way so I hope it will be here soon.

[64Rivvy]

Jan,

 

If that doesn't work let me know.  I have a tool I fabricated to make it very easy to measure and fit a custom sized pushrod for any MC.  I had to do this when I converted my 69 Camaro from power brakes to a hydroboost setup.  I can send you pics of the tool and how to make it.  Took less than 30 min to make and cost is less than $6.  Hopefully you can figure it out without going that route, but if you do need to just let me know.  Good luck.

 

Raul

[SwedeDownUnderR63]

The Dual Master Cylinder conversion is completed

 

The Dual Master Cylinder is now in place (I got the correct MC from Tony Gentilcore, a PBR P7210 instead of the one that was incorrectly delivered). The new MC has a 36.5 mm deep dimple length (41.5mm on the old), it was also slightly different in other lengths so it took down the difference to ~4mm which could be adjusted with the screw.

 

This is what is in place/have been done:

• We (metal woman assisted) replaced all the brake lines with the pre-bent stainless steel ones that I got from the USA (www.inlinetube.com). They were almost a perfect fit.
• The special new brake lines that we created between the new MC, the Wilwood Proportioning Valve (P/N 260-11179) and the connection to the front and rear brakes (now separated) were finally made with standard brake lines (we gave up on trying the stainless steel as we were not successful with those lines, too hard for unexperienced brake specialists to get perfect). A total of 4 shorter brake lines were cut, deburred, bent and flared using Brakequip Professional Tubing Cutter BQ602, Eastwood Pro Brake Tubing Flaring Tool, Eastwood Tubing Deburring Tool, and the Tubing Bender Rolling tool (all from  http://www.eastwood.com/shop-equipment/brake-tools.html).
• The Proportioning Valve was fixed to the car through steel work made by Ann-Kristin. (The washers in the pictures have been replaced).
• We replaced the rear brake hose with a new one (original, not braided), the front ones looked OK so we kept them as is for the moment. Hoses from Cars (http://www.oldbuickparts.com).
• We plugged the rear of the brake distribution block, I used a plug from inline tubes for that.
• We plugged one of the front outlets (there are two) from the proportioning valve with a BQ19 plug from www.brakehose.com.au.
• The new MC became a PBR P7210, the square O-ring was reused from the old MC.
• We used a BQ110 joiner from www.brakehose.com.au to connect the rear brake line to the new brake line (made by us) that connects to the Proportioning Valve. The rear brake line was also fixed at a new point to make certain that it stays in place.
• We adjusted the Wilwood Proportioning Valve a little bit first, but had to go back to max difference during the testing by the Engineer for the certificate as the rear brakes locked. There is a protection cap on top of the proportion valve adjustment screw (Australian, especially NSW according to my engineer, requirements).
• We used DOT4 brake fluid as I intend to drive the car a lot.
• The windscreen washer plastic bottle had to be replaced and the new one installed in the front as the Proportioning Valve had to be installed in that location. The new washer came with a pump so I rewired such that I no longer is depending on the old broken washer motor.
• The brake light (only for 1963) was connected to the Proportioning Valve switch and works fine.

Thank you to all great appends in the Forum at ROA’s website) that made this work possible. I have learned more than I wanted to know about brakes, hopefully I will forget it soon such that I only have to worry about brake shoes for a while

 

You might ask why we did it ourselves? I tried to get someone to do the conversion but they either didn't want to do this kind of work or they were to busy. At least I got all the tools in case I would need to do it again.

Edited February 27, 2016 by Jan Norback (see edit history)

[telriv]

Just for a FYI. That rod does NOT come out from the front. the whole booster needs to be taken apart. It's the last piece. I believe this is true right up to '66.     '67 was the 1st. yr. for the removable pin.

 

 

Tom T.