I just slapped a set of ART cryo'd front discs and new pads on the truck, and I never opened the system, just clamped the pistons back into the caliper. Now it just seems mushier than it was with the old brakes. Also the brake pedal kinda goes down in steps. Is my hydra-boost going, or should I just tryto bleed the calipers?

 

Hard to say, but I'd go ahead and bleed 'em. Only takes about 2 quarts to flush the whole thing, if they haven't been done recently. I used Valvoline full-syn (of course!! LOL) DOT 3/4 fluid in mine.

 

id bleed them starting with the furthest away from the master cyl. .... pass rear,driver rear,pass front, driver front. it takes 2 folks unless you gotta pump

 

Did you open the bleeder when you pushed the pistons back in? I guess you are supposed to do that. Might be a brake line starting to go since they are rubber...

EDIT: Did you also bed the pads in properly? I had a set on the '92 that weren't bedded in properly and it stopped funny until they were heat up real good. Just a thought

 

It is hard on the ABS system if you don't open the system while pushing back the piston.. But, yes I would bleed all 4 wheels like Steve says..

 

I'd also try to get as much of the old fluid out of the calipers as possible, you'll have to open up the brake system by having to remove the calipers and turn them upside down but it's well worth it after you reinstall with all new fluid. I have heard that just clamping the caliper pistons back in to allow new pads isn't the best thing for an ABS setup of for a MC for that matter. I loosen the bleeder screw before using the c-clamp to allow the old fluid in the calipers to be removed, once the pistons are far enough back just tighten the bleeder screw then remove the c-clamp. I hope this helps.

 

I usually open the bleed screw, but on my passenger side, the damn bleed screw snapped off from corrosion, so I either have to get a new one or a new caliper, so that's why I did it that way.

 

If it's that corroded you would be better off with a new/remanufactured caliper, I replaced the fronts on my truck when I did my drilled & slotted rotors.

 

Yeah I'll definitely get around to that soon, how much were yours?

 

How is it hard on the ABS system? What part of the ABS is stressed?

I'm curious where you heard that because in all my reading of the Ford tech site for doing brakes, I've never seen where it was cautioned that pushing the pistons back could damage or harm the ABS system.

Standard bleeding procedures will flush any old fluid from the caliper as well as the lines. Bleeding the system doesn't just flush the lines.

Why open the bleeder screw before pushing the pads back? That just introduces air into the system. The proper way is to remove the brake master cylinder filler cap and remove enough fluid until brake master cylinder reservoir is half full.

Stewart

 

This is what I did. Never heard of opening the bleed screw -- like Stew said, that just sucks air in there...

 

Need to bleed the air out.

 

In all my years working on cars, trucks, motorcycles I've always used an old brake pad and a c-clamp to push the pistons back in, never an issue, as others have said, standard bleeding procedures will flush the entire system, as stated earlier, when doing so remove some fluid from the master cylinder so it doesn't overflow (brake fluid eats paint) Sounds like you still have air in there.

Dan

 

Let me clarify what I said in my post. If there is any crud in the braking system from the fluid braking down either through heat cycles, absorption of moisture, particles of rust from aged brake lines it ends up where, in the lowest point of the system which of course is the calipers. Now if you force the pads back while not relieving the pressure( loosen bleeder screw while clamping pistons back) this crud while be forced back through the ABS control box and/or the master cylinder. The master cylinder is just basically a couple of inline pistons with o-rings which slides into a machined bore and seals the action of the pistons which gives us our brake pressure upon pedal application, through into the mix the backwashed brake fluid that over time has become less than ideal you now have brake fluid with enough grit in it to score the bores and o-rings inside the MC. The ABS is even more sensitive to ANY particles, it has valves and servos in it(ever had a trans valve body apart and see how tight the tolerances are) any bit of foreign matter will hang the valves and cause problems. I realize that opening up the brake system may bring up the fact that you can introduce air into the system but it shouldn't happen the way I bleed the calipers, let me explain. You take the caliper off now while holding the caliper with the bleeder screw in the upright position take an old brake pad and a c-clamp lay the pad against the pistons of the caliper and apply a little pressure to the clamp which is just enough to get the pistons starting to move inward now break the bleeder screw to allow the pressure to be released, you can even take the bleeder screw all the way out if you want because no air will be ingested into the brake system unless you allow the pistons to move outward in their bores(not going to happen while clamp is applied) which causes a vacuum inside the caliper. You can now just tighten the c-clamp until it just bottoms the pistons in their bores now re-tighten the bleeder screw. If for some reason air was ingested or you turned the caliper upside down to remove all the fluid just reinstall caliper with the pads installed and gravity bleed the system by filling the MC and break open the calipers bleeder screw and while seeing the fluid come out of the caliper take a wrench or some other object and tap on the caliper to help jar any air bubbles that could be adhereing to the inside of the caliper, after seeing no bubbles you can tighten the bleeder screw and top off the MC and you are ready to go. I have gravity bled all my vehicles with no problems but I would pressure bleed them to be on the safe side. I know this was long winded but I hope this helps in any way.

 

Hey Mongo,
Mine were from Advanced and they were about $55 each lifetime warranty. I believe they came with slide pin boots and/or other hardware as well.