Customs Brake problem...

My son Jess , have a Oldsmobile Holiday 1963 Rocket 88...He did a conversion ,from drum to disc brake up front and original drum in the rear... that contain a proportioning valve in the kit, new after market booster, master cylinder new from Jegg good for a Toronado earlier model ...Everything is supposed to fit for is car... my problem is...He did like around 5 or 6 miles ,and the brakes are so hot , I can't touch is wheel , and the front brakes look like there stock on front...smoke on 4 wheels ,and we wait a half hour before restart the car and drive to is house , like 5 minutes from mine...Is it possible that the proportioning valve as to do something about it or else ...sorry for the accent and spelling ...Don View attachment 5415215

 

Lots of things could do that. But I’d start with the pushrod from the pedal to the booster and then the booster to the new master cylinder. If when the brakes are hot and you crack a fitting at the master, brake fluid squirts out under pressure. Easy to not have enough free play when you set it up. Been there, done that.

Good looking car, enjoy.

 

First, I'd look to make sure the pushrod from the pedal to the booster had a little gap.

 

Thanks ,...I'll make sure to check the pushrod from the pedal to the booster, I thought that was the problem at first ...then it was to dark to work ...My son said ...that he modified the rod , and I was not there to held so?...

 

Crank the pedal rod in by around 1/8" of an inch and go for a ride. If you know the thread pitch, you'll know how much travel-per-turn. Like a 3/8-24 thread is .041 per turn. a 5/16-18 is .055" per turn.

Or measure it with a decent scale...

 

You say kit. Was the BOOSTER, MASTER CYLINDER and PPV included in the kit? Did the 'kit' come with the BOOSTER and MC assembled? Who was the supplier/vendor of the kit?

If all four wheels are hot, then you have an application problem (dragging) and others have said how to check for it (open a front and rear bleeder when hot).

The MC, it appears from the photo that it is a DRUM/DRUM MC. When did GM go to front discs? I am FORD orientated but all brakes work the same. If a DRUM/DRUM MC there will (should) be RESIDUAL PRESSURE VALVES in both circuits. If the GM PPV has an additional RPV (common in GM) in it separate from the MC, they (REAR BRAKE CIRCUIT) will not work properly together.

There is a specialty gauging tool available to properly set the BOOSTER to MC rod clearance. The actual PB BOOSTER actuating rod clearance (and adjustment procedure) should be shown in the correct SHOP MANUAL.



Beautiful Car! Brings back memories of the competition back when ...

 

The kit came separate but he order them all from the same company ...and as for disk brake ,they offer him the kit from a Olds Toronado , I think is from 1969 or else ... Now the problem is solved and the push rod was to tight ...Now it work like new ...Big Thanks to all of you ...This site is awesome...

 

As for myself ...I'm still working on my 51 Ford Vic... Kustom

 

Sorry! for the large diameter wheels pic... we are still waiting to get some kind of original wheel for it . we didn't like it too ,but he just bought and still waiting to receive it...