Hi,
I have a 1989 F-150 2WD with a I-6 engine.

I just replaced bearing, rotors, calipers and shoes on the front.

Rear WC are about 3 yrs old.

Replaced Brake MC with an AC Delco.

Ok the brakes work and I am driving it, but....

There is no real "Hard" pedal feel?

Truck stops ok but just does not feel right?

I did the usual test checking for leaks in lines calipers or MC!

Brake booster test, all good, vacumn good!

Oh yea aso bled the ABS valve in the left rail drivers side!!!

I can not think of anything else to do???

Any ideas???

 

did you bleed the mc on the bench before install?

did you check your pedal travel?

whats the pedal feel suppose to feel like?

you might just be overthinking it.

I dont have to force my pedal down, I can barely touch the brakes, and the truck slows down. wouldnt say its a hard pedal.

you might want to replace all the rubber lines also if its that bad,

driver side passenger side on the front, going to the calipers.

and there is one or two rubber lines on the rear of the truck. one is on the frame underneath the truck bed on the drivers side.

if your steel brake lines are old, check for leaks/pinholes, and check your wheel cylinders. if you replace your wheel cylinders, replace them as a set.

whenever you bleed your brakes, you have to bleed all 4 and the ABS module.

I have a 'might vac' brake line bleeder,

you might have a air bubble or two in the brake line somewhere?

maybe adjust your rear brakes?

 

Hi,
Thanks, forgot to mention also new brake hoses on front also!

The rear to the WC is all hard line.

This truck has been in Central Florida just about for ever! (no road salt!)

I have a mighty vac also used that then went to the one man system with the tube and bottle, using the MC for pressure.

Before my brakes were good but old the MC was 12 years old and I had a bad RF wheel bearing so said to hec with it and replaced everything.

This truck has close to 300,000 miles on it!!!

With the engine OFF the pedal stops HARD, but

With the engine on driving, I don't get that hard stop of the pedal?

MC leaking by, even though it passes that test shut off???

 

Hi,
Forgot to mention...

Yes! I did bench bled the MC.

I did it by using the plugs in and pushing in the piston til it would move no more?

 

There is a rubber line going from the frame to the rear axle. It is steel line again at the axle.

Is this soft pedal while driving?

With the engine off pump the brake pedal three or four times. Then press hard on the brake pedal and hold. Is it soft now? Does it slowly sink to the floor?

 

Hi,
Thanks, no when the motor is off and the pedal pumped a few times and then pressed hard it stops and stays at the same place (no sinking)

 

Hi,
I'm also looking into making a "reverse" bleeder as that would push any air out to the rsevior, in case there is still air in the MC???

 

That is not the correct procedure and you may have introduced air into your system that way.

Most new MC's come with a bench bleeding kit in the box. If not, you can get one at the parts house. There should have been two fittings and two short lengths of hose and maybe a wire in that kit.

The fittings go into the MC, the hoses attach to nipples on the fittings, then the wire holds the ends of the hoses below the fluid level inside the reservoir. When you pump the MC piston, the fluid is returned to the MC reservoir and because the hoses are below the surface of the fluid, the air is purged and prevented from re-entering.

Generally, I leave the kit in place when I install the MC, then hook up one line at a time to prevent excess air in the system. Bleeding still needs to be done and I think the right order is RR, LR, RABS, RF, LF.

 

I never heard of such a method. I'm not saying it doesn't work, just that I never heard of it. I only used the method of where you hook a tube to each brake line outlet and the tubes loops back into the top of the master cylinder.

At any rate I think the front brakes system would have gotten properly bled just by bleeding the front calipers.

If you haven't bled the rear brakes, because I understand you didn't work on them now, I would try bleeding the rear brakes in the normal manner on the chance the master cylinder didn't properly bleed. Just my suggestion.

 

Congratulations, you don't have any leaks. I may not be understanding you, but is the pedal hard on that last press? There is air in the system if it is soft or spongy.

The brake booster might be going out if the pedal is hard or stiff on that last press. I believe it is also characteristic of the power brakes installed on these older trucks. My old '69 was the same way. I replaced everything but the steel lines in the frame, and on the rear axle. The pedal still felt soft while driving. I had the brake booster replaced, and that seemed to help with pedal feel.

 

Ah, I hate when that happens. Number 8 posted while I was typing and thinking how to word number 9. I am a slow typer and an even slower thinker.

 

I'm not sure how I beat you to it. I was typing one-handed, making two mistakes in each word. Not a good night here for typos.

 

Hi,
Thanks, ALL WC and calipers (also ABS valve) has been bled numerous times with different methods!

That's why I am here now as I still don't have that HARD pedal that I did have???

All I can think of is still air in the MC?

The AC Delco MC came with only the two plastic plugs and instructins on how to bench bleed with them installed.

As you pump the piston, the air comes out the resevior till the piston will not move anymore?

So I am still confused what the problem is and why I'm thinking of the reverse bleeder?

http://www.hotrodders.com/forum/new-...re-184246.html

 

Hi,
Well..I just ordered an "oil can" reverse bleeder.

I can't afford the $375 dollar one!

I think with all the test being positive I just might have a bit of air still in the MC?

I'm hoping going UP gets it out!

All the fluid is now new so not worried about hurting the ABS valve and pressure will be "easy"!

Thanks for the help, Gentlemen!

I will let everyone know if this works when I get it!