STOP ME!

2+2=cool · Dec 9, 2007

Hello everyone,

I’m hoping you can help me with a problem I’m having with my 66 fastback: it has manual breaks, disks up front from a 65 GT Mustang and drum in the rear.

My problem is it’s just not breaking like it should. I really have to press hard to make the car come to a complete stop. When I bleed this system the fluid comes out in a trickle.(all four wheels)

Is this an indication that my brass splitter/proportioning valve is not right? (This came off and 67 mustang) With the exception of the brass splitter and the calipers everything is new on the car: lines, calipers where rebuilt, new wheel cylinders in the back. Master cylinder is new (two reservoir ) Any help in this would be very much appreciated.

Chris

enferno · Dec 9, 2007

is the master cylinder made for disc/drum?

fasttback · Dec 9, 2007

Where did you put the proportioning valve? Do you know if either the front or back brakes only lock up if you step on the brakes hard?

My '66 manual disc/drum brakes take some effort, while my '67 power brakes make it too easy.

1320stang · Dec 9, 2007

enferno said:
is the master cylinder made for disc/drum?

That there is likely your problem. Also, the rear reservoir is for the front brakes and the front one is for the rear.

zookeeper · Dec 9, 2007

I was going to suggest that as well. It's very easy when assembling a fresh system to assume the front resevoir is for the front brakes. It's not.

2+2=cool · Dec 9, 2007

As far as i know the master cylinder is correct...unless they sold me the wrong one. The splitter is monted underneath the master cylinder and the line coming out of the front is going to the rear.

12sec67 · Dec 9, 2007

how are you bleed the brakes...

1320stang · Dec 9, 2007

Then I'm guessing you have a drum/drum M/C. My buddy put Granada brakes on his '68 coupe, the damn thing was a pain to push thru the staging lanes at the track. Later he put a new M/C on it, this time a disc/drum. It's like a whole different car pushing it and it stops a LOT better too. Turns out the drum/drum M/C doesn't release enough when you have discs, and they drag at the discs. Discs require more pressure than drums as I understand.

gjz30075 · Dec 9, 2007

The master cylinder should have two different size bowls, the larger one for discs, and, as said, should be in the rear. Also, the brass splitter is not necessarily your proportioning valve, unless you bought it that way. In '65/66, the brass splitter was simply that: a distribution block to channel the fluid one way or the other. The proportioning valve was totally separate.

1320stang · Dec 9, 2007

I could be wrong, but I think that stock splitter does have a proportioning valve in it, but it's not adjustable, maybe it's just ont he factory disc/drum cars, but I believe even on the drum/drum cars as the front brakes typically have more brake pressure than the rears. My car is a factory disc/drum car that still has the stock fruitjar M/C.

fasttback · Dec 9, 2007

1320stang said:
I could be wrong, but I think that stock splitter does have a proportioning valve in it, but it's not adjustable, maybe it's just ont he factory disc/drum cars, but I believe even on the drum/drum cars as the front brakes typically have more brake pressure than the rears. My car is a factory disc/drum car that still has the stock fruitjar M/C.

It would be good to know if he has the distribution block and proportion valve on his set up...along with the right MC.

Stock 65-66 disc brake vehicles were configured with the KH disc brake setup, which includes a distribution block and an adjustable KH proportion valve mounted near the MC. In 1967 the distribution block was still mounted in the same location (wired with an idiot light this time), but the non-adjustable proportioning valve was mounted near the rear end.

rc4mike · Dec 9, 2007

i have a 65 GT but if i recall it only had the dist block...no proportioning valve. I added one on the rear line along with new MC made for disk/drums. Have new disks up front and drums at rear. Mine seems to need a lot of force to stop at times and not much at others. Seeme like the MC is working intermittently. My vacumm may not be enough i am thinking. Also, cant get front of or rear to lock on hard braking.

1320stang · Dec 9, 2007

Well I'll be dipped, I was looking at a pic of my M/C area on my homepage and sure enough, there is a proportioning valve below the distribution block. It looks pretty rusty.

2+2=cool · Dec 10, 2007

Thanks for all your help everyone.
Sorry it's taken me until this morning to get back to you all, with a 10week old son now in the mix it's getting harder to find the time to get in the garage. DON'T worry you wont see and add in the newspaper saying "66 fastback for sale Must sell, baby on the way" ANYWAY....
I was calling the splitter the proprotioning valve, I don't have a proprotion valve...(sorry my bad) perhaps I need one. When I blead the system I started at the wheel that was furthest away form the M/C and worked my way around. Someone had mentined that perhaps the splitter is not correct. ???I'll crack the lines at the splitter and see how the "Flow" is comming out of the M/C.
Again I thank you all for your help it's been great to have all this input.

STOP ME!

2+2=cool

New Member

enferno

Member

fasttback

New Member

1320stang

zookeeper

2+2=cool

New Member

12sec67

Active Member

1320stang

gjz30075

Member

1320stang

fasttback

New Member

rc4mike

Member

1320stang

2+2=cool

New Member

Similar threads

STOP ME!

New Member

Member

New Member

New Member

Active Member

Member

New Member

Member

New Member

Similar threads

Privacy & Transparency

Privacy & Transparency