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OK. Went back and looked at all the pics.. GOOD JOB. Did the top for the master cyl. come with it or did you have to make it? (for the remote fill)
M/cyl cap was part of the assembly - you have to purchase a remote fill master - you can't retrofit a standard reservoir one - came with the master cylinder (RH outlets) which included the cap with barbed brass fittings for the rubber hoses - included the hoses, clamps, and the reservoir.
NOTE: There were several 'incidentals' along the way - but this is the core stuff. Everything else is a parts or hardware store away..misc fittings, clips, etc..
I noted after driving that the pedal needed to come up a little as it was bottoming out on the floor and therefore not giving my 100% pedal travel (more like 95%).
I removed the assembly and notched it to give it a slight upward pitch (~10 degrees). Photo shows before welding the notch.
Gives a much better pedal response now.
Like I said, this is a learning process for me too.
Overall, this conversion has been fantastic, and I will likely do it to each car as I service the brakes.
However, I have noticed that after I've driven for a little while, the brakes feel like they're dragging (or not releasing 100%) - I've read that these residual pressure check valves can be the culprit - does anyone have experiences with this? I have half a mind to just eliminate the check valves, but I'm not sure what the implications might be.
Love the look of what you did to get away from the Treadlevac , did you solve problem with the brakes not releasing by removing the residual pressure valves? Thanks for the article! Larry
Love the look of what you did to get away from the Treadlevac , did you solve problem with the brakes not releasing by removing the residual pressure valves? Thanks for the article! Larry
the release issue was due to the adjustment of the push rod and not the valves
I've been investigating this same project only my '56 has manual brakes. I was thinking I could do a frame mount unit where the original master cylinder sits and the unit I was going to use was one made to add power brakes to a 55-59 chevy pickup. What do you guys think?
Yes it does! I would have to cut the bracket that came with it and reverse it or make an entirely new bracket, OR actually mount it on the other side of the cross member as-is and make the arm that pushes it extend down instead of up. It would suck to have to fill it with fluid when it's under the floor though. The space between the cross member and the steering gear is only about 13 inches and the whole thing is 12 inches...
I have seen something similar to that used but mounted on the outside of a reinforced air box and S 10 swing arms used rather than the original peddles. You lose the original look (which isn't for me) but you can eliminate the treadle vac by doing this....Tedd
I really like what Olds Dad did, I'm only balking at the cost. Those parts add up to $500 for just switching out the master. I just feel like the booster and master shouldn't cost $400. I may go that route or just convert to original power brakes. I'd feel safer with a dual resivoir though...
I got rid of the entire fabbed assembly for the pedal and reinstalled an OEM hanging pedal assembly with the same master / booster setup
The pushrod thread on the booster is 3/8-24 so I bought a ball joint assembly from McMaster Carr (6058K38) which has a 3/8-24 ball stud and cut the ball stud out of the shank and then used a 3/8-24 coupler (90977A170).
This ball stud fits perfectly into the back of the pedal where the original treadle vac push rod would have fit
It now works perfectly, stops perfectly, and looks 100% original.
Yes, I know you're supposed to have the correct pedal ratio (which is the whole reason I fabbed up the assy to begin with) but you can't argue with results.
I would not hesitate to do this again on another car (less the big ugly fabricated pedal assembly).
And yes, you will have to change the OE wheels to use the discs - if anyone knows a way around this I'd love to know because I want to use the dog dishes but they won't work on the later wheels - the full disc covers will though so...
Awesome, thank you very much for replying to my questions. I don't suppose you have any photos of the new pedal set up with how's it's attached?
Even with this pedal ratio, how does it feel? Nice and firm?
Thanks again for the reply.
Chris.
Car is in storage but I will get you some pics as soon as I can.
Pedal feels natural and solid - I also talked with a guy who did the same thing with a dual diaphragm 7" booster on a '55 S88...so I guess it will fit, but even with the single it stops great...biggest thing is to make sure you have good vacuum to it - the hose I had had collapsed so I wasn't getting vacuum and it made the brakes horrible - replaced that with a good hose and all is well - I retained the vacuum tank along the frame rail also - not sure if that was necessary, but I figured it couldn't hurt
The pics would be great thanks! Trying to picture it in my mind but it's not working lol.
Yes, I had planned to keep the vacuum tank regardless, if the engine dies and your going down hill you will still have full braking capacity.
I planned to renew the vacuum line itself when I do the swap. I've never driven the car but all the stories I hear and photos of other peoples cars who the brakes factory power brake set up has just died without warning causing an accident doesn't give much confidence.
Followed your thread and it was very helpful. The only difference is I used a Wilwood master cylinder that has the proportioning valves in the master cylinder and then had 12" flex brake lines made to connect with the brake lines. when it came to the petal assembly I used the original petal and modified it so it looks original ( a lot of cutting and welding ) I don't know if it would have gone as smooth as it did without your help.
Followed your thread and it was very helpful. The only difference is I used a Wilwood master cylinder that has the proportioning valves in the master cylinder and then had 12" flex brake lines made to connect with the brake lines. when it came to the petal assembly I used the original petal and modified it so it looks original ( a lot of cutting and welding ) I don't know if it would have gone as smooth as it did without your help.
I got rid of the entire fabbed assembly for the pedal and reinstalled an OEM hanging pedal assembly with the same master / booster setup
The pushrod thread on the booster is 3/8-24 so I bought a ball joint assembly from McMaster Carr (6058K38) which has a 3/8-24 ball stud and cut the ball stud out of the shank and then used a 3/8-24 coupler (90977A170).
This ball stud fits perfectly into the back of the pedal where the original treadle vac push rod would have fit
It now works perfectly, stops perfectly, and looks 100% original.
Yes, I know you're supposed to have the correct pedal ratio (which is the whole reason I fabbed up the assy to begin with) but you can't argue with results.
I would not hesitate to do this again on another car (less the big ugly fabricated pedal assembly).
And yes, you will have to change the OE wheels to use the discs - if anyone knows a way around this I'd love to know because I want to use the dog dishes but they won't work on the later wheels - the full disc covers will though so...
Great conversion man, as I just got a 55 S88 I've been looking for a brake upgrade...
Did you ever get a chance to take pics of the new set up of the pedal assembly.
I am new to this forum (at least posting). I have read your thread with great interest. I am considering the same modification for the same reasons as you have done.
I just would like to confirm something. I understand you got rid of the entire pedal assembly you worked on, a great effort, I must say.
To be clear with the current working set up you have now....
You have bolted the 7in single diagram booster and 1in bore master cylinder assembly directly to the toe board, just as the original configuration that Olds did back in the day. This being with a 1:1 pedal ratio with no mechanical advantage. You are using a vacuum reservoir tank along with the booster to augment the need for vacuum. And you are happy with the pedal feel and braking capability.
I hope the above statement is true. I would really like to know your feedback on this, because it would be very useful in my future work.
I am new to this forum (at least posting). I have read your thread with great interest. I am considering the same modification for the same reasons as you have done.
I just would like to confirm something. I understand you got rid of the entire pedal assembly you worked on, a great effort, I must say.
To be clear with the current working set up you have now....
You have bolted the 7in single diagram booster and 1in bore master cylinder assembly directly to the toe board, just as the original configuration that Olds did back in the day. This being with a 1:1 pedal ratio with no mechanical advantage. You are using a vacuum reservoir tank along with the booster to augment the need for vacuum. And you are happy with the pedal feel and braking capability.
I hope the above statement is true. I would really like to know your feedback on this, because it would be very useful in my future work.
Thanks in advance.
Yes to all your questions - however, on my next one I will use a dual diaphragm 7" booster only because I now know that it will fit - make sure you use a large diameter vacuum line like the OE and that it's a material that will stand the heat down there near the exhaust - my first attempt was a Home Depot tubing which eventually collapsed giving me no vacuum.
I scratched the fabricated pedal assy because, while I had the higher mechanical advantage, I couldn't get it to apply the pedal force "in line" with the booster - and there wasn't a lot of room for adapters, joints, etc - so I went back to the OE pedal and it is great - same pedal effort as you'd expect from the TreadleVac and same stopping power IMO - I'd say the dual diaphragm might eliminate the need to have the aux vacuum reserve but I'm not positive - I will do the same conversion on the next one I get onto the road - I think you'll be happy with it.
I say go for it - cheaper than the TreadleVac and unless you're building a 1000 point concours show car most people will never know the difference.
a BIG " thank you” olds dad, followed this post, and might be doing this in the future. i had my OE rebuilt, but this looks to be a very good upgrade...being OE is single piston.
Okay, so I am ready to get a disc conversion kit for my 55 super 88. There are soooo many threads that I am having trouble deciding what worked best. I need a kit. I need a dual master cylinder....and it wont fit, so it has to be mounted on the firewall and it could maybe be from a corvette? Can someone just come do this already?
For the discs I like disc brake mike's setup: http://www.discbrakemike.com/ Also, www.rocket88.se covers brake conversion but you have to translate the site from swedish to english which google will do for you.
First, great article, i'm going to follow your guide on my own Olds project. And there is one question that i need an answer for? My Olds has 15" original rims and you has written that they will not fit after doing the disc brake conversion. So can you tell me exactly which rims i'm looking for to replace original rims?
Hope you can help me, I have to have rims shipped half way around the world so they must fit :-)
BR Peter
I know that you will need 15" wheels off of a disc brake vehicle, I think a mid 1980's Chevrolet truck will work. I am building a resto mod with my Oldsmobile because it has the Chevrolet engine in it. I used the steel 18" wheels off of a 2014 Camaro on my car and had to use wheel adaptors for them.
Can someone tell me why the OE wheels cannot be used?
Anyone got a pic of the difference between an OE wheel and the replacement for Discs?
Cheers.
The stock wheels hug the drums on the rear quite tight, they won't clear the calieprs. If you go on the scarebird website they list a disc kit which only includes the wheel end components that does fit the factory wheels.
The stock wheels hug the drums on the rear quite tight, they won't clear the calieprs. If you go on the scarebird website they list a disc kit which only includes the wheel end components that does fit the factory wheels.
Thanks for that mate...I wasn't keen at all looking for another set of wheels plus the extra cost.
This is without question the best thread on converting to a modern power booster and dual master cylinder on the internet. I've seen that Battle Born set up that uses the hanging pedal and looks like garbage. Olds Dad cracked the code here. When my treadlevac goes, this is the way I'm going to go. Awesome work.
wow its been a few years .....but i followed OLdsDad lead ... had a few hic ups but this 2ton rocket now Stops on a dime .
little info ...
First had a guy in N california rebuilt my OE (Sunny) ...had it leak ! took it apart and not ALL SEALS REPLACED .
Frustrated , i followed OldsDad info.
here are pics :
JUNK FROM EBAY this is off a Malibu ....(dont recall the yr. early? 2010 Sorry ) Re drilled mounting holes Scarbird Kit Fit good ... A little fight but was able to use the original paddle . do recall re drilling the Brake Pad to the right to accept the push rod
October 27th, 2012, 11:03 AM
