Brakes: Brake pedal pad

[BrianC]

I had my hydrovac fail three yrs ago, had it rebuilt and decided to upgrade the chassis mounted m/c with a Turner dual. This, with the hydrovac have not been sucessfull, a hard pedal and no ability for a panic stop. Read a thousand posts, tried a thousand things, ive had it with the brakes from Hell on the Hawk. Had much help from the club, many suggestions and responses, however somehow “ALL” this info had been deleted and the Forum doesn’t know why.
I decided to put the original m/c back in, along with the distrubtor block and front and rear RPV’s and hope for the best.
In adjusting the pedal travel, the manual recommends 1/4” to 3/8” free travel from the pedal pad before the stroke begins. Problem is theres no pad on the car and I’d like to know the thickness so i can adjust the pedal stroke. I can make a quess and install a substitute for the pad.
The brakes on this car have cost considerable $$$$$ and enormous amount of time, im ready to give up and sell it withno brakes......thanks...dis-hearted.

[Ross]

All that is necessary is that there is enough free play at the pedal so that the piston in the master cylinder is not depressed at all when the pedal is released.

[BrianC]

Thanks, figured that might be easy enough. Wasn’t sure if there were critical measurements.

[BrianC]

Thanks, figured that might be easy enough. Wasn’t sure if there were critical measurements.

[BrianC]

I presently have a 10# RPV for the rear drums from the distributor block. I had a 2# PRV form the Hydrovac to the front discs, but now that its plumbed back to original and that RPV is at the output of the Hydrovac is going to the distributor block, im thinking this is wrong? In order to use RPV up front i would either have to plumb it different or put one in for each front wheel.
I’m thinking that this extra 2 lbs of pressure is wrong? Do i really need a RPV for the front or will the Hydrovac provide enough to keep the pads to the disc???

[JoeHall]

I feel your pain, with the substandard brakes, but must ask, if there is no pedal pad, how are you pressing the brakes?

As for the 2# RPV coming off the output side of the HV, it is not likely a problem. However, to check it, push the brakes while sitting still in your driveway (transmission in neutral) then immediately get out and try to push the car. If it rolls freely, there's not enough residual pressure to affect brake drag. You can also check by coming to a stop on a slight incline. After pushing the brake pedal, if you take your foot off the brake, the car should start to roll again. Either way, you are checking for brake drag, when the pedal is NOT applied. Another way is to stop the car after a few miles, get out and use the back of your hand to feel for excess heat around the front rotors. (Do NOT use your fingertips to touch the rotors.)

Perhaps you are expecting too much out of the brake system. What exactly do you expect it to do in a, "panic stop"? When moving how fast? If moving maybe 30 MPH or less, it should lock up in short order. If moving 50 MPH and up, is may haul down quickly, but may not lock the front wheels up.

Pad and shoe materials can also determine the brake system's, "personality". There are materials that will turn any car's brakes into junk. And there are materials that will make the best of a marginal system. Generally, softer, quicker wearing pads perform the best. While those that last longer do not perform as well. I prefer very soft, with max initial grab, and minimal fade. I am currently using EBC, "Green Stuff" pads on two of the Hawks, and still using Hawk brand HPS (high performance street) on the 3rd Hawk. I can definitely tell a difference, and will someday get round to installing Green Stuff on the 3rd Hawk.

Just rambling, I guess, but hope this helps.

Also, see this thread: http://forum.studebakerdriversclub.c...tuff-quot-Pads

[BrianC]

The pedal pad im referring to is between the outside firewall and the pedal. They refer to i in the shop manual.
The “panic stop” im referring to is at a low speed. I have a hard pedal with and have to use a very heavy foot to come to a stop. If i slam them, its a slow stop. Originally, when i first got the Hawk, the power brakes were better than newer models, hit it hard and you’re into the steering wheel. Pads and shoes are like new, wheel cylinders and calipers are good, no leaks, bleed it to death with no good results. So, if this experiment fails to get anything positive, I’ll have to take a serious at the Hydrovac again. Had it rebuilt but i hear so many people have had so many problems with them even after rebuilding.
Thanks for the info, im fishing, hoping to find the AH-HA! Solution.

[StudeRich]

A Hard Pedal, with Power Brakes WITH a Hydrovac Booster, is most always a Bad Booster.

However, IF you have the Original Single Master Cylinder for Drums and you have not removed the Residual Valve and Rubber Cushion in the back of the Bore as well as those other two RPV's?? They also are NOT needed with Rear Drums and Front Turner Discs.

It should be no different than a stock '63 GT with Power Discs. IF you have the Dual Diaphragm Hydrovac for Discs.

The only difference is, you MAY have self energizing Standard Drum Brakes in the rear (you can reverse the "Wedges") unless your Car HAD Power Discs to start with, OR you have replaced them with the Non-Self energizing Rear Drum setup for front Discs.

ALL these "Issues" are why I would NEVER try to install Disc Brakes on a Drum Brake car with the under the floor Master Cylinder.

My Turner Brakes work PERFECTLY on my '64 Daytona that HAD Factory Disc Brakes.
The '63 to '66 Larks and Lark Types and Avantis with Power Discs make for a Sweet stopping Car, by converting to Turner Kits, and IMHO... THAT's IT!

[Studebakercenteroforegon]

There does seem to be some occasional pissing and moaning about HydroVacs on this forum - but remember these are being successfully used every day by tens of thousands of industrial trucks and they must be doing their jobs satisfactorily.
So their use goes far beyond being used by grumpy Studebaker Drivers. If If needs rebuilding or replacing - do it!

[doofus]

Listen to Stude Ricc! sounds like a bad booster,,,, Period. Luck Doofus

[Skybolt]

A Hard Pedal, with Power Brakes WITH a Hydrovac Booster, is most always a Bad Booster.

However, IF you have the Original Single Master Cylinder for Drums and you have not removed the Residual Valve and Rubber Cushion in the back of the Bore as well as those other two RPV's?? They also are NOT needed with Rear Drums and Front Turner Discs.

It should be no different than a stock '63 GT with Power Discs. IF you have the Dual Diaphragm Hydrovac for Discs.

The only difference is, you MAY have self energizing Standard Drum Brakes in the rear (you can reverse the "Wedges") unless your Car HAD Power Discs to start with, OR you have replaced them with the Non-Self energizing Rear Drum setup for front Discs.

ALL these "Issues" are why I would NEVER try to install Disc Brakes on a Drum Brake car with the under the floor Master Cylinder.

My Turner Brakes work PERFECTLY on my '64 Daytona that HAD Factory Disc Brakes.
The '63 to '66 Larks and Lark Types and Avantis with Power Discs make for a Sweet stopping Car, by converting to Turner Kits, and IMHO... THAT's IT!

Don't understand your logic. I have had a couple of cars, Studebakers, that I swapped out the front drums for discs, not a Turner kit though. I have not had any trouble. My current Stude I used the original master, under floor, no other changes, no RPV's, no booster, no pulling anything out of the master, no problems. Why wouldn't you change to front discs? Simple.

Len

[rkapteyn]

It always helps to tell us what car you are having problems with.
Was it a disk brake 1963/64 Studebaker Hawk originally?
These cars had a different Hydrovac that was problematic.
Studebaker supplied an improvement kit for these.
If it is a Subaru , I can not help you.

[BrianC]

This is front factory disc w/mc chassis mount. I fear the rebuild i had on the booster was woefully inadequarely done. Jsut about finished re-installing the original m/c, im trying anything and everything to slove this. Keeping my fingers crossed.

[rkapteyn]

Again Brian , is it a Hawk or Lark?
Different Hydrovacs!
From your comments I deduct that it is a Hawk because only the Hawk used a MC on the frame.
With Turner brakes , you do not need a booster.
The OEM 1963/64 Hawk boosters need the improvement kit.
Jim Turner gives excellent customer service and is easy to talk to , give him a ring

[345 DeSoto]

Don't understand your logic. I have had a couple of cars, Studebakers, that I swapped out the front drums for discs, not a Turner kit though. I have not had any trouble. My current Stude I used the original master, under floor, no other changes, no RPV's, no booster, no pulling anything out of the master, no problems. Why wouldn't you change to front discs? Simple.

Len

Same here, on my Sky Hawk. Not problem #1...