brake issue

[Hubert Cumberdale]

Hello gentleman. I have a bit of an issue with the brakes on my 64 comet.
My problem is the brakes are spongy regardless of how much I bleed them.
The set-up is discs all around (granada front discs and 97 explorer rear discs)
They are all of the single piston orientation.
My buddy and I used 3/16 line on all of it and plumbed them into a gutted fox body distribution block.
I have a proportinating valve under the driver side for the rear brakes.
My original master cylinder was a 15/16 bore that had the same issue so we figured we would try the 97 explorer master cylinder since it was larger 1 1/16 bore and free.
But its still doing the exact same thing and to be honest I'm kinda at a loss on where to go from here.
I have double checked all the fittings for tightness and can't find any leaks.
Any ideas?
All help is really appreciated !

[A/FX]

The problem could be the gutted distribution block. The block no doubt contained a residual check valve. You can install an in line residual valve and achieve the same results. Wilwood makes them in different lb. ratings. Did you bleed the system with the caliper bleed screw facing straight up? You may have to remove the caliper, insert a block of wood between the pads that is the same thickness as the rotor and bleed the whole system again.
You should have also bench bled the master cylinder before installing it.
I hope this helps.

[Kingspeedy2]

3 thoughts that may be remote Perhaps the adjustable link rod between the pedal and master cylinder is miss adjusted and the MC isn't moving far enough,
Sounds like with the bigger bore MC that volume of fluid being moved shouldn't be a problem.
secondly and this may be a shot in the dark as I don't know the condition of your car and firewall, Is the actual master cylinder flexing were it mounts to the firewall?
Thirdly ..and I don't want this to be insulting especially because I am no brake expert myself,but I have had 40+ cars and bikes and have blead a few. how are you bleeding the brakes?
The old Pump and Hold ..Pump the pedal ..hold loosen the bleeder method?
Plastic hose on the bleeder into a jar full of fluid method?
If you really want to be sure its bled use a hand vacume pump,method .they are about $25 bucks in Canada .
another.


My former father in law who was a mechanic taught me a good way to bleed but a little on the messy side...
Brake fluid is water soluble so usually washes off concrete pretty good

1. While wearing a rubber glove (to prevent fluid injection into your finger)
loosen the the bleeder at the farthest point away while the finger with the rubber glove is over the bleeder hole
Have an assistant pump the brake pedal slowly while your finger remains on the bleeder as a cheque valve.The fluid and air will escape..past your finger without air being drawn in because of your finger
You will also feel any air coming by..It a lot faster than pump and hold..once its clear move on to the rear left then front right and finally front left
Also only crack your bleeder the minimum required

good luck

[CALIFORNIA CALIENTE]

I agree with AFX,I think the gutted block is causing your issue!Most major mail order outfits carry residual brake pressure valves,they can be installed anywhere in the system,try just the fronts first!!Also check that the link from the pedal to the master is the correct length [just barely contacting the MC plunger]. JMO , ROY.

[Hubert Cumberdale]

Hey guys,thanks for the responses. I wound up going out there today and pulling the rear line off the master cylinder and plugging it up and after that I had strong pressure.So I know the rear is the problem..I will look into the residual pressure valve on the rear line and see if that makes a difference.Thanks again!

[Comechero65]

Hey guys,thanks for the responses. I wound up going out there today and pulling the rear line off the master cylinder and plugging it up and after that I had strong pressure.So I know the rear is the problem..I will look into the residual pressure valve on the rear line and see if that makes a difference.Thanks again!

I think you still have air in the line to the rear. When I did mine I thought I would never get all the air out. Took a ton of brake fluid and lots and lots of pumping to get it purged out. The rear was the worst. Once I got that clear of air the front bled out just fine and the brakes became hard as they should.
Want to make the job easier and no second person needed, order this kit from HF. I found this AFTER i did mine. Too late to do me any good. The Mrs was my pedal pumper. Kept her busy that day. Used to use the kids for that but they are never around anymore. Sure gets tiring getting up and down to keep the mc filled with fluid. The kit reduces that with a large bottle that keeps the reservoir filled for you. It also helps to replace the bleeders with auto-bleeders.

http://www.harborfreight.com/brake-flui ... 92924.html
If you have an air compressor it works with this kit and is real easy.
Ron

[Hubert Cumberdale]

Comchero thats actually the bleeder I'm using. I did bleed the rear again today with it but quickly ran out of fluid.The brakes did stiffen up just a little bit.I plan on getting more DOT-4 tomorrow and giving it another go before I try the residual brake valve. Just want to make sure.Thanks!

[popscomet]

I thought of this as soon as I read your 1st post,,but just stayed out of it,til I just read you are using dot4 fluid,,,yrs ago back in the 90's when we redone wife's 1956 ford and added disc brks,I blew the old lines out with #10 thinner and air and of course made all new lines for the frt disc,I used brks from a 1976 Granada and mc and valve,,,,,,I went to a CYCLE SHOP and bought dot 4 or dot 5 fluid as it won't eat paint,cause backing plates and calbers are powder coated,as the lca's,,,car still has perfect brks but with that fluid they have always felt just a tad spongy,I was told that would happen on a car,like I said,after all these yrs the car still has great brks,,my wife has driven this old ford several yrs even out of state and if it doesn't have good brks she would have balled up on me.....so what I am saying is it might be the fluid your using....JMO.....good luck ..pop

[Rocket989]

Late reply as I've been away...unless there's a HUGE difference between the size of the front and rear brakes, with all disc - a proportioning valve is not good. You want ALL the pressure you can get to ALL the brakes. Echo the comments on any residual valve, although the 10lb. (used with drums) would maybe just cause a too tight thing on the rears. A 2-lb. residual is often used with rear discs to stop chatter (if present) or on any brake system where the MC is lower than the calipers...

A 15/16 SHOULD be fine with your parts. An 1 1/16 should take a gorilla to push on a manual system...something is up somewhere!!! Was it a manual brake car to begin with??