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Mike S.
Mike S., Classic Car Mechanic
Category: Classic Car
Satisfied Customers: 7369
Experience:  A.S.E. certified with 25+ years experience.
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1979 Ford F150: me, Im driving and I..Ranger XLT..XLT 4x4..short bed

Customer Question

"Help me, I'm driving and I can't stop"....... I have a 1979 Ford F150 Ranger XLT 4x4 (short bed). Over a year ago I had the rt. front brake line (rubber end) bust on me. (Good thing for me I was parked @ the time). My mechanic friend began what was a lengthy, and somewhat expensive brake repair....Over the period of about 2-3 months we ended up replacing, FIRST, the front brake line (where the problem started), No Brakes......ALL TOGETHER, we ended up replacing the Master Cylinder (3 times)...the Brake Booster (twice)...the front Calipers and pads...the rear brake Cylinders (shoes were OK)...New (aftermarket) Proportioning Valve... Brake Lines from proportioning valve-BACK had been previously replaced and in great shape... The only Brake Lines NOT replaced, are the Coil Lines from the Master Cylinder down to the Proportioning Valve....... Everything was checked, and rechecked for tightness, positioning, and alignment BEFORE Bleeding the Brake Fluid...Even the Master Cylinder was "Bench Bled" BEFORE installing it....... No matter WHAT we do, we can't create Brake Pressure in the Pedal, and what pressure there IS built up, is very quickly lost after pumping up the pedal....AND, That pressure will only apply the Rear Brakes, NONE in the Front Brakes..........I am VERY desperate to resolve this issue, QUICKLY. I am even entertaining the idea of RE-installing the ORIGINAL Proportioning Valve (I still have it). Someone PLEASE help me! I said at the beginning....Ya COULD drive it, but it ain't gonna stop. (460 Roller w/Comp Cam, Holley 600FS, C-6 A/T, 4X4, twin pipes w/40 series Flowmasters). Winter is here and I NEED my baby.
Submitted: 5 years ago.
Category: Classic Car
Expert:  Mike S. replied 5 years ago.

Ok, I have one question. How much intake manifold vacuum does that engine create with that roller cam?

Expert:  Mike S. replied 5 years ago.
Also, in what order did you bleed the wheel cylinders/calipers?
Customer: replied 5 years ago.
We bled the front first, not sure which side though.
Customer: replied 5 years ago.

Don't know the answer to your Q about the intake vacuum. Not a mechanic. Have one doing work for me.


Expert:  Mike S. replied 5 years ago.
Ok, the order they should be bled is the furthest away from the master cylinder to the closest, so that would be RR,LR,RF and then LF. Bleed them all again and make sure you get fluid out of each one and no more air.
Customer: replied 5 years ago.
I just called my mech. and he said that IS the order he bled them, AND that he even used an "Extraction System"(?) to bleed them. He said there was NO air bubbles when he was done.
Expert:  Mike S. replied 5 years ago.
Then the best thing to do for now is check for a leak.
Customer: replied 5 years ago.
Have checked several times for leaks, even using Brake Clean to be sure we're not missing anything. NO LEAKS!
Customer: replied 5 years ago.
IS IT POSSIBLE, that the aftermarket proportioning valve might not be the right match that I need??? (I'm grasping at straws now)
Expert:  Mike S. replied 5 years ago.
Well then, if everything is on correctly and no leaks, then all I can say is if your mechanic used an "Extraction System" to bleed the brakes, ask him if he held open the proportioning/metering valve while bleeding. If you use foot pressure to bleed you don't have to hold open that valve.
Customer: replied 5 years ago.
I can tell you from being there to help on occasion, that he would have me to pump up the brake pedal during the bleeding process. I DID however, notice that when the truck was up on the lift, that there is an electrical connection wire coming out of the proportioning valve, and that it was NOT hooked up to anything(?).
Expert:  Mike S. replied 5 years ago.
That wire is for the brake warning light. Hook it up. Have you ever bled brakes before? Do you know the procedure? How was you doing it?
Customer: replied 5 years ago.
Now I know why my brake light doesn't a matter of fact, as long as I've owned the truck that light hasn't worked. I'll try and find the other end of that wire and hook it up tomorrow. AS to your Q's about my experience in bleeding brakes? I haven't any, that's why I have a mechanic working on it for me....I bought the Prop. Valve on one of those online sites (can't remember which one), and I remember reading there, that the cylinder/plunger inside the Prop. Valve has to be "centered"(?) in order to work properly??? (Like I said, I am NOT a mechanic. I AM however, very observant. I NOTICE things.)
Expert:  Mike S. replied 5 years ago.

On that proportioning valve. The plunger has to be centered in order for the brake warning light to work properly, if not the light will always be on. To center it, if you have to you just open the opposite bleeder from the last one you bled and press the brake down untill the light goes out then tighten the bleeder.

The reason I asked about whether you have bled brakes or not is because if you let up on that brake pedal any at all while any of those bleeders are open you will suck in air.

Mike S. and other Classic Car Specialists are ready to help you
Customer: replied 5 years ago.

My sincerest apologies to you "heavy chevy 396", for taking so long to respond to your latest answer. I've been mulling over, in my mind, all the answers you've given me up to this point, and everything you have suggested has already been tried and tested.......I STILL THINK that I will try putting the original Prop. Valve back on and check it for CENTER positioning. The loose wire connection that I was telling you about fits the connector on the original Prop. Valve to a "T". Once all that is done, and if it still doesn't work, then I don't know WHAT I'll do things for sure though...I'm NOT getting rid of my truck.Cool


Even though this matter is yet to be resolved, I am going to accept your answer, as I do not wish to take up anymore of your time....Again, I'm sorry for the delay, and whenever we DO resolve this issue, I will log onto this site and leave a message for you, explaining what our findings were....just in case the answer may be beneficial to you.Wink

Expert:  Mike S. replied 5 years ago.
Thanks, I would appreciate that!