Technical disc brake swap issue..still got a soft pedal

!!! DAMN !!!​

 

Dead thread.........
The OP didn't even have the courtesy to reply since Jan 6 2020.
He's probably figured out it was a self induced cluster***k and went away with his tail between his legs.

This is why I am now cautious about helping on brake threads

 

Roger that... every thread with a similar situation end with I found the problem without stating the problem or the guy going ghost, I read through pages on pages attempting the suggestions, I will post my solution (hopefully once found) the purpose of these forums is to help others not just yourself... that is my intent

 

I... like others have spent money on these kits to increase the safety of vehicles... and because we are doing our own builds (rather it be more cost efficient or because we want to do our own builds... it just something about saying I did that) anywho these kits are advertised as diy or straight bolt ups...and they should be, I will get to the source of the issue (hopefully with a little help) and I will not leave others in the dark! I didn't come this far ... just to come this far. More to follow...

 

The Wilwood kit I bought included instructions on how to center the calipers before pads were installed. The centering washers were included as were wheel spacers if needed.
I’m not saying that stock part from various cars will not work properly; but engineered kits with proper MC’s for power and non-power, prop valves, pedal ratio, and even rear wheel cylinder diameter if using drums are all part of an efficient safe brake system.

 

I think some brake kits are more equal than others (pun very much intended!).

Chris

 

I think of the guys on here who, for one reason or another, don't like to post and try to figure out there troubles by reading these posts.

My favorite disc caliper is the D-52 rebuilds that N.A.P.A. sells. The machine work is amazing on them. The seals are always sitting perfect when I take them apart to clean, lube and check them out before putting them to work.

I once got 60,000 miles out of a pair of them on a big 64 Bonneville that had the Scarebird brackets.

Just recently, I had the front end up and gave both front wheels a spin and they both spined very eaisly with out any grabbing or dragging like most disc brake systems have.

Having a car that works against itself is one thing that bugs the living shit out of me.

N.A.P.A. used to sell some of the best disc brake pads I ever used. They were rivited and looked like the old Greyrock shoes. They had the perfect amount of metallic that stopped nice and straight without all the squeaky noise of some pads.

In my area the brake pedal is as important as the gas pedal.

 

Well believe it or not

The issue was the brake booster

After swapping an other and different disc brake kit and i was still having the same issue.

Also swapped multiple master cylinder with different bore size

And without counting the infinite number of time i bled the brakes using every tevhnic you cant imagine.

Different ratio pedal as well

The only thingh left untouched ,or swapped out , was the brake booster

I got a good one from summit
One that look the same
I installed it with the extact same adjustment at the pin/rod that goes behind the master cylinder

And it works --- right away---

Myth buster i know

Yes i confirm --the booster ---was giving me a low spongy pedal and not good breaking

I still have the booster and will keep it for ever
I think that booster is somewhat an unicorn

A lot of guy here were really nice helping

But some were not pleasant this is why i never went back on here.

 

Did the camber issue get resolved? It's been a long time! We've had a virus come and go ( or not go?) since this all started, it's been that long.

Frustration manifests itself in many ways!

Chris

 

Well I swapped / installed an other brake kit
And that kit fixed the camber
But not the brakes issues

I post a picture of the kit
I think for the price they really good
Bigger caliper and rotors.
And more simple as well.

 

from first post,

from today,

Only thing that changes with engine on, is vacuum to booster.
I am sure that this thread will help others.

@Vincentnova - thanks for returning to your thread and posting the outcome.
Regarding the negative comments - if you don’t come back to answer any posts, you are effectively wasting peoples time who are trying to help, so understandably, they get frustrated………

 

I had the same issue with my kit. Bypass the valve and see if you have a good pedal. My system never work with a valve in it. And it does not lock up without it. If the pressure is not correct the valve won't work. They just throw a bunch of parts together and call it a kit.

 

Well I’ll be damned! Absolutely none of the information we were given actually indicates a booster problem of any sort. So either the way boosters/brakes work has been incorrect forever or we weren’t given accurate information.

 

I went with NO booster on my car, it would have chewed up valuable real estate. Plus I may have had a vacuum issue with the cam. It stops like a mid-'70's Chevelle with manual power disc brakes.

 

There is something not quite right here. If the booster fails, it basically becomes a solid push rod. If the rest of the system is working correctly, there is no way the booster can cause the pedal to go to the floor. Just a really heavy pedal.
I am glad the problem has gone away; sometime good luck happens. I can't help thinking about the pile of parts purchased, now hidden in the corner that did not cure the problem.
Garpo

 

I call B.S. on the "fix".

Early on in the post we know that with the front brake hoses clamped, the pedal is high & hard. This isolates the issue to the front calipers. Either air, mounting, bearings, etc. If it was a master cylinder or booster issue, then stopping performance would be an issue, not pedal "feel". If it was a booster issue, then the pedal would feel "normal" but the brake performance would be poor. The whole scope of the thread was focused on a "soft" pedal

I am fighting this issue on a 52' Mercury with a similar conversion utilizing GM brake calipers. If I clamp the front hoses, I get a high and rock solid pedal. I believe in my case to be the caliper adapter brackets and mounting. With everything installed and a helper pumping the brakes to bring the pedal up to something close to a pedal, I can see huge amounts of deflection in the caliper mounting brackets. If I remove the caliper pins, the pedal is much improved and no bracket deflection because the caliper is not springing around anymore. Talking with the conversion kit supplier I get the expected answer of, "thousands of these kits have been installed with no issues".

This has been frustrating to say the least. Firstly, because I spent big money on the Wilwood kit and Wilwood master cylinder only to find the Wilwood kit will not work with the dropped uprights. Add insult to this, I buy the shoebox kit that will work with the dropped uprights only to be banging my head with still no brakes!

To my defense, the Wilwood kit says it will not work with aftermarket spindles....not aftermarket uprights. The dropped uprights use the stock spindles.

I have done 4 conversions over the years. This is the first one that has gone so sideways, I'm pissed blind and ready to hang the drums back on which worked perfectly.

Anybody want to purchase a discounted Wilwood conversion for a shoebox Ford/Merc.?

Any suggestions with the current shoebox conversion kit?

 

I just want to relate my personal experiences with gm calipers. The normal brake hardware kits being made for these calipers are horrendous. The sleeves and o-rings do not have anywhere close to enough clearance to allow the caliper to easily slide back and forth along the mounting pins.
I take the pins and remove enough metal at the tips so they can slide in the small o- rings on the outer edge and sand off the sleeves so they slide in the big o-rings.
Without the pads you should be able to slide the caliper back and forth. If not they will never work right.

 

I ordered a Speedway Motors front disc conversion kit for my 51' Ford about 1-1/2 years ago, I spent almost that much time figuring out the issue I was having. I'm always busy at the shop, so I didn't have that much time to mess with it. My issue was, driving, hit the brakes at a stop sign or whatever, fine, next time to hit the brakes, nothing! Brakes would work if you pumped em real fast about 3 times. I triple checked everything, no air in the system, new master cylinder too. Pulled the wheels off and something was sure wrong. The tops of the rotors were actually rubbing on the caliper pins and was spitting out the rubber pin bushings in the calipers. The caliper pins didn't appear to be setting straight, looked like they were cocked. Hmmmm, so I pulled the rotors, disassembled the caliper brackets, reassembled the caliper brackets, left the bolts loose. Clocked the assembly up and over since there was a little wiggle room in the holes. Tighten/torqued everything, reassembled the calipers on the brackets, noticed the pins went on 100% better, no binding. Reinstalled the rotors and now the pins are above the rotor and not rubbing. So my conclusion was, the caliper/spindle brackets were slightly cocked enough to make the caliper pins rub on the tops of the rotors. I also readjusted the master cylinder rod to the brake pedal, made it a little looser. I used a early 80's Mopar brake pedal assembly and didn't put the return spring on it when I had drum brakes, it seemed to be more responsive without the spring. I also installed a return spring on it now. Brakes work awesome now, got about 60 miles on it, after screwing around on it for a year and a half!