OK Update!

Thanks for all your help up until now.

I decided that it had to be an issue with that stupid master cylinder and it was!

I was getting no fluid but air pressure out of the rear of the master.
So I went ahead and replace it.
So far EVERYTHING in the brake system is BRAND NEW. ( Except the center front hose, which they dont have at the auto parts store and the metering valve )

So I bleed the brakes in the correct order and have pressure!!

Took it around the block and noticed that the pedal fades to the floor and I loose brakes. I can however pump the brakes and get pedal again.

I am assuming this is my poor bleed job or something, how does one gravity bleed?

THANKS!

 

Hi there,

Im glad you found the problem. Did you check the master cylinder like i suggested or did you have another method for doing so? Either way im happy your truck is back on the road

 

To get all the air out you need constant flow of fluid thru the lines. This is why pressure bleeding works so well. The next best bleeding system is the vacuum bleed. Remember you need to flow a good bit of fluid to get all the air out off those long runs like the right rear. Did you bleed the master cylinder first as I described earlier? Do the front and rear of the master then go to the wheels in the order crazzywolfie posted. If you use a good clean catch jar between the vacuum pump and the wheel cylinder/caliper you can reuse the brake fluid as long as it is flowing clean when you have replaced the whole system as you have.

 

I looked for bubbles but didnt see any.
I basically just took off the lines and tested it as if i was bench bleeding it.
Put my fingers over the holes and had my buddy pump the brakes.
When I felt pressure I let my finger loose and fluid squirted out of the front hole but NOT out of the rear hole.
I did this over and over and felt pressure from both holes but never got fluid from the rear one.
After I replaced the master I got fluid out of both holes. (well during the bench bleed.)

Like I mentioned though, I still have some mushy pedals.

I did bleed the master as it said in the Haynes Manual.
And then I bleed the brakes in the correct order. RR, LR, RF, LF

Im going to go ahead and re bleed them again I think.

 

New brakes and still no pedal? Sounds about right for an 80's Ram

 

OK I am really getting frustrated.

I have bleed the brakes countless times, (15?) and STILL no pedal!
I have replaced EVERYTHING now!
What am I not doing right?
I had pedal ONCE then it went away after the car was on for a few min.

Please help, at this point I'm going to actually pay to have it done, but I'm so broke, lol.

 

did you adjust the rear brakes before you put the drums on? if your drums went on too easy then you need adjust it till it is a snug fit. this could cause your pedal to go super soft.

 

haha believe it or not I had forgotten that until about the 8th time around bleeding but I have since adjusted them and tried to bleed after that.

I gave up tonight and cracked loose the fittings at the master again to double check I had pressure there and I do.

Im going to Re-Bleed the stupid master into itself tomorrow but other than that Im stumped.

Is it normal to have more pressure out of one of the master holes than the other? the front hole has way more pressure than the rear.

Also, can you buy plugs for the master? because then I should theoreticaly get brake pressure in my pedal if I could cap the master. Right?

 

can you explain this statement a bit better because it make no sence. do you have the caps on the reservoir when you are pumping the brakes. if you don't have the caps on the reservior while your pumping that may be the problem. have you looked for any possible leaks in any break lines?

 

A properly functioning master cylinder operates like this. The front piston in the master cylinder is the same diameter as the rear so it cannot give more pressure than the rear by design. The front piston is actually moved by hydraulic pressure that is trapped between the two pistons. If the rear piston fails the front piston is then pushed forward by direct contact from the rear piston stem.

When you bench bleed the master are you putting the open end of the bleed line so that it is submerged into the fluid inside the reservoir? Not doing this can introduce air into the fluid.

Are you talking about capping the masters outlets to see if the master alone gives you a hard peddle? Yes you can buy plugs for the master by buying a bench bleed kit. I would think theoretically that you would get a hard peddle with plugs installed but the plugs I have seen are plastic and I don't know if the are substantial enough to hold pressure. You can make plugs by using both ends of a piece of brake line. Cut off 2 inches of each end and then fold the line with pliers back on itself twice and gently hammer the tubing closed after each fold. Be sure you leave the threaded fitting on the tube before folding.

Did you have good solid bakes before you tore into them?

Have you checked the power brake booster? There is an operating check and an air tightness check. If it is not air tight it can give the symptoms you are experiencing. Do not replace it unless you are sure it is bad as they are very expensive. A leaking vacuum tube that supplies the booster can cause this.