65 beaumont sd rag, brake booster/master cylinder

jasonlaing · Veteran Member

65 beaumont sd rag, brake booster/master cylinder

SD 396 · Poncho Master!

It could be the pedal adjustment or if you are using an aftermarket booster the pin length may not be correct.
Are the brakes dragging at all?

jasonlaing · Veteran Member

The brakes arent dragging, I adjusted the pin so there was 1/8" play

kelico · Poncho Master!

is there a proportioning valve involved? just curious

jasonlaing · Veteran Member

I didnt think that I needed one as it is drums front and rear, the m.cylinder is made for drums all around

RAILSKINNER · Addicted!

i'm thinking because you state that it is a dual master cylinder, there is probubly going to need a proportioning valve.

over the winter I will be in the process of installing 4 wheel disc brake onto my 65 Beaumont hard top,with newer style A arms top and bottoms, along with the newer arms for the rear end suspension as well. power booster and dual master cylinder too. i have to have a certain type of valve for disc /disc too.

Brian · Addicted!

Did you change the wheel cylinders? Are the wheel cylinder bore sizes for the 66, with the dual, same as 65's with a single?

JerryA · Addicted!

It sounds like you might have a disc brake master cylinder .With a drum brake system you don't need a proportioning valve.

-- Edited by JerryA on Sunday 13th of November 2011 09:26:24 PM

jasonlaing · Veteran Member

The master cylinder is for power drum brakes all around, I have to check the wheel cylinders.

m21bud · Addicted!

Drum brake friction material is often sensitive at cold temps. Get them heated up and see what it feels like, if it free's up it's the friction. Order new shoes with "organic" material. Don't order the "better" or mettalic ones, they grab too hard. The good thing is the organic are also the cheepest.

jasonlaing · Veteran Member

Just went for a ride today, the pedal went further down after the brakes warmed up, the pedal went close to the ground. Im going to rebleed the whole system to double check. Any other ideas?

65sssd · Poncho Master!

jasonlaing wrote:
Just went for a ride today, the pedal went further down after the brakes warmed up, the pedal went close to the ground. Im going to rebleed the whole system to double check. Any other ideas?

Do me a favour and drive in reverse and pound the brakes. Try it twice. Then take it for a drive and see if it helps. Drums expand and you might have not adjusted your pads correctly. As long as the adjusters aren't seased this should help. Paul.

68sd396rag · Poncho Master!

Did you keep the same proportioning valve from the original 65 lines?If you used a dual resevoir master then I would put a proportioing valve from a 67 and up drum btakes car.66 and down masters are all single resevoir master cylinders,67 and up are all dual resevoir and thus came with a different proportioning valve mounted on the frame.If you use a disc brake system then 67-70 used a metering valve that is located on a bracket below the master and then runs fluid from there through the frame mounted proportioning valve.71 and up use a large cast iron proportioning valve that suited as a dual purpose valve for disc brake cars. GM did this for a reason-I am sure of that.

jasonlaing · Veteran Member

There is no proportioning valve on the original 65 system and I cant find one for a 66-dual with drum brakes all around.

Brian · Addicted!

66 had dual master for drum/drum, no valve, with a splitter block with and extra inlet from master for the rears for the first part of the yr and then they went to drum/disc and valve from then on from what i have been able to find out.

4SPEED427 · A Poncho Legend!

No, I think you have to find 67 and newer stuff if you want to have a dual master setup. As far as I've ever seen there was no dual system on any 66 GM product.

Brian · Addicted!

You are correct Carl. I posted without checking typo first.

jasonlaing · Veteran Member

Found another hole in the brake pedal up higher, probably for the power brakes, tried to adjust rod to fit but it seemed to hit something in the master cylinder or ? Any ideas? Maybe it is hitting the "seal" between the firewall and the booster?

beaumontwagon · Guru

The long shoes are in the back and the short ones in the front? I think that makes em lock up if theyre backwards.

Bluebud456 · Member

jasonlaing wrote:
Found another hole in the brake pedal up higher, probably for the power brakes, tried to adjust rod to fit but it seemed to hit something in the master cylinder or ? Any ideas? Maybe it is hitting the "seal" between the firewall and the booster?

The rod that goes into the master cylinder from the power booster is pre-loading your master cylinder. You need to shorten that rod to have 1/8 inch clearance to the pocket it sits in so the master cylinder can come back to rest and release the brake pressure. You can also space the master cylinder out. You essentially have a miss matched booster, master cylinder set.

jasonlaing · Veteran Member

Ill try that....thanks