My son has a 57 Dodge wagon that was converted over to 4 wheel disc brakes several years ago. At the time, he installed an unknown brake pedal, master cylinder and a 7" power booster (came with the project car uninstalled). The car has been on the road for about 6 years and he has experienced high brake pedal effort since. He has arrived at the point he is trying to make the car more driver friendly. He has reached the conclusion he needs to go to a manual disc brake set up (has no space for a larger nor a dual booster), and it appears Wilwood has a complete bolt in set up that will work on his car. We are looking for any comments regarding real life experience the Wilwood brake, master cylinder, and proportioning valve set up.
No sir, I always use the speedway stuff, but I don't think that you'd have any issue with Wilwood. I'm curious to see the current setup, do you think the bore size on the master cylinder could be the culprit?
The general opinion is anything smaller then an 8" brake booster is ineffective, and he has a 7". The motor does not allow a larger booster. The question was presented to Wilwood about the size of the master cylinder bore, and the brake pedal ratio, using the disc brake calipers he has (they offer services for such info). Wilwood says he needs a 6 to 1 pedal ratio and a 1 1/8" master bore for the (Monty Carlo single piston front and 2000 Explorer 8.8 rear) disc brake calipers he has, complete with part numbers and prices for everything from them. He just got this info today and has not had a chance to measure anything. We are seeing what the guys with experience here think about the Wilwood stuff. The current pedal ***embly, booster, and master cylinder kit he has now are a no name kit that came with the project car when he bought it, more then 10 years ago (the car has been on the road about 5 years now, but he wants to start driving it more). It looks like one of those Ebay kits with the "Corvette" booster and master cylinder in the "beautiful" yellow cad color. He is not opposed to replacing that entire set up. The current brakes work and stop well, but require a pretty high pedal effort. He is currently going through a list of things that bug him, in order to make the car more driver friendly, and the pedal effort is one of those things.
Have done a bunch of Wilwood installs as described. Used 7/8-inch master cylinder for a 4-wheel disc setup and it worked great. Good pedal modulation and no spongy pedal that you can sometimes get with a vacuum-***isted booster setup. One thing to keep in mind, swapping out the master isn't going to correct an incorrect pedal ratio, which sounds like the problem as per described. You want at least 5:1. See below in regards to figuring out what the ratio is now... Make sure the ratio is within spec before spending more money on a master.
Sounds like the brakes are already there but just need to be a little better. Small changes can make a huge difference. A small increase in pedal ratio. Small decrease (1/16") in master diameter. Booster actually working, the single 7" don't do much, but they do something, but do nothing if they're not working. Too hard a pad compound. Starting over seems illogical when they are actually working, to a point. Chris
Based on your drawing, I had always thought the ratio would be (A - B) / B. Or is that what you’re inferring? Thanks.
I’ve used the hanging pedals that put the master(s) under the dash. 1” for front, 7/8” for rear. No need for a proportioning valve as the one I used has what they call a balance bar, IIRC.
What does he have for brake calipers and pads? The front of my 47 Chevy has GM metric brake calipers. When I replaced my “parts store” brake pads with Wilwood street performance pads, I got probably a 30% improvement in braking ability and lower lower pedal pressure. The difference was surprising. More to your question, in my oval track racing days I used a lot of different Wilwood components, and was very happy with all of them.
Yep. I’m no hydraulic scientist. I have used the Wilwood tech advice. I’ve gave em the info for the brakes used and they recommended a bore size, prop valve and or bias adjuster.
Gene, I have a Wilwood M/C on my coupe and have used their proportioning valves on different builds and all have been fine products. A little on the spendy side but worth it IMHO.
Thanks guys. Looks like Wilwood might be the way for him to go. As a side note, someone asked why he was willing to start over. His current setup with the booster has a 4 bolt booster mount at the firewall. The Wilwood master cylinder they suggested is a 2 bolt cylinder, so an adapter would be necessary (which they have priced out at around $50), considering the time involved with making the adapter, buying theirs doesn't sound out of line. Then if you take into consideration he may well have a pedal with the wrong ratio, which could also position the master cylinder at the incorrect position for the adapter and any master cylinder after the booster is gone. We have already had an issue with the connection between the current pedal and the push rod into the booster, a couple years ago. That issue was resolved, but the memory of it is still present. Using Wilwood's pedal ***embly with their master cylinder eliminates the need for the adapter and should align the master cylinder with the brake pedal push rod. I'm pretty sure if he goes with the Wilwood pedal ***embly and the master cylinder, he will also use their recommended brake proportioning valve as well. He may have to change the brake lines connected to the master cylinder anyway, once the booster is removed. After the booster is removed and the new brake pedal and master cylinder ***embly has been installed, if farther brake improvement is needed, I'm sure my son will be talking to Wilwood for farther instructions or corrections. , Getting everything from the supplier that has designed the system has huge advantages. Almost all of what he already had will be disconnected when the booster is removed. He has given this a lot of thought.
When my son bought this wagon, everything involving the front disc brakes was included with the car and was all new (as less then 6 months old at the time) and was still in the boxes, along with all the new front suspension replacement parts. Other then the parts required to make the car roll around on the wheels, everything else was gone. He simply installed all of the new parts. The rear axle was changed out for the same reason, nothing but what was required to make it roll on the wheels was present. He bought a rust free CA rolling shell and a complete parts car, both ***led, for under a grand, 10 (or more) years ago. The garage the CA car was in caught fire and the car was pushed out and saved, but the removed chrome trim was damaged. The parts car had all the parts needed to complete the build, but was a rusty heap. We built the car and he drove it a couple years before he pulled it apart to have body work done that never materialized. Then he upgraded the drive train ad got it roadworthy. 100 miles later, it was in a shop to get an exhaust leak fixed (by the shop that did the exhaust), but the car got caught in a flash flood (up to a couple inches of being completely covered with water). We got the car out of the flood and replace or rebuilt everything. The body work was done, and he has been driving the car for 5 or 6 years. He has decided he wants to drive it more this summer. He has a list of things he wants to improve on it. The brakes and window weather stripping are on the top of the list. The rebuild after the flood took the car outside of the HAMB because of the interior (nothing near original that came off the parts car could be saved) and the drivetrain (the Hemi is too new), but the car exterior still fits. I will have to see if my wife has pictures of the car on her phone.
A friend of mine changed his Chevy from an automatic to manual and had it done by a local shop. They used a Wilwood aluminum master cylinder and aftermarket pedal set (not Wilwood) bolted to the firewall. From day one the car had excessive pedal pressure but my friend just thought it might be normal. After a couple years one day the master cylinder failed. Examination of the master cylinder showed heavy wear on the piston top and in the bore of the master. It was finally figured out the problem was misalignment of the shaft from the pedal to rod pushing the piston. To look at it it looked straight but it had to do with the swing arc of the pedal. I know the OP was talking about brakes and not a clutch slave cylinder. However a hard to push brake pedal could also be misalignment issue. Also if a Wilwood master is installed careful attention should be paid to alignment. Your mileage may vary.
I have been using the complete system from Wilwood for 6 years on my 1956 Ford. I do not use a vacuum ***ist can. The MC is 7/8” by Wilwood’s recommendation. The pedal ratio is not as good as it should be but braking is way better than the original 4 drum stock brakes. I have room under the dash and with the pedal rod angle to drill another hole in the pedal arm to improve the pressure but so far do not see the necessity. Wilwood calipers are 4 piston instead of the standard 2, this may make a difference I don’t know. I do know if you change rear ends to make sure your rear wheel cylinders are a compatible size for your installation ie: power or non-power. From what I read on your installation with a vacuum can perhaps just a different MC with a smaller diameter will make a difference or a larger vacuum can. For some reason correct brakes for every application “fits all” is a very bad idea. Many variables exist and must filtered thru for you needs and expectations. A 57 Dodge is not the same as a 32 highboy.
The brakes on the wagon work very well, it is that the pedal effort is on the high side. At this point, there is no intension to change the calipers or the brake pads. The brake pedal ***embly, the master cylinder, and the proportioning valve are the target point at this time. He feels that any noticeable improvement will be enough to make him happy. There is not enough physical space to put a larger diameter or a longer vacuum can (booster), that left side valve cover is a royal pain to pull off now. Eliminating the booster will free up some needed space.
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