Having serious brake issues...

[Maysdad199071]

Hello im new to the forum. Might b on the wrong forum but worth a shot...my brakes were getting bad so i decided to tackle them. Started out with front pads and rotors...calipers ended up being s**t so i changed them also...bleed the system..brakes were stiff will the truck was off..turn it on goes to the floor..changed master cylinder out..bleed the system from back to front no change..goes to the floor.. Abs light turned on.. Changed out the module and pump..changed the wheel cylinders out used a scan tool to bleed the air out of the abs system. Goes to the floor.....nochanged...what in the hell is going on lol...??? They get kinda stiff with the truck off.. Once the truck runs. No brakes. Any info or clues on what next.. Would b awesome...thanks. Dealership dont know what to do.

 

[iLikeEggs]

Pull the fuse for the ABS while you do this. Sounds like you've got air trapped in there. Start all over. Bleed from the furthest wheel first. It will take a lot of foot pumping and you will run through some brake fluid but you will get it. If you can eventually get to a firm brake pedal, then finish it off with a gravity bleed overnight. Also, did you bench bleed the master cylinder before you installed it?

 

[Chip18]

Don't overlook the "obvious" all bleeder valves need to be on top! I did it the other way many years ago. Finally took it to a shop ... yeah I was embarrassed! I only mention it because apparently someone on another forum ... just did the samething!

And I have always used one of these guys with great success.:

https://www.summitracing.com/search...der=ascending&autoview=sku&cm_mmc=ppc-google-


Most likely on Ebay also but you'll need one with the adaptor for GM cars and trucks.

 

[Chip18]

I had heard that with "ABS" vehicles if the pump gets air in it, they can be a bear to bleed. The "Dealership" had no answers??? Hmm that's odd?? At this point ... you've changed a whole bunch of stuff ... to much too soon. So now even more variables to contend with.

So ... that sucks ... still ... back to basics! It's gotta be something going on??? At this point ... (hope it's not your only vehicle??) I'd go with the "Motive bleeder" fill it up with two or three quarts of brake fluid. Pump it up to 14 lbs (I think that's standard but check for your vehicle.)

So pump it up and grab a "beer" and then do "nothing!" If there are no leaks the gauge should stay at 14 lbs ... if there is a leak ... then the fluid is going somewhere???

Vehicle jacked up in the garage, clean cardboard under each wheel, the Master Cylinder and the ABS Pump. If it's leaking you should be able to see it??

And another place to check is inside the vehicle, where the pedals are look for signs of leaking inside. Oh yeah and be sure and wipe down the area where the MC attaches to the Brake Booster. You want it clean and dry. When you pump up the "Motive" check there first to look for leaks.

 

[Maysdad199071]

Pull the fuse for the ABS while you do this. Sounds like you've got air trapped in there. Start all over. Bleed from the furthest wheel first. It will take a lot of foot pumping and you will run through some brake fluid but you will get it. If you can eventually get to a firm brake pedal, then finish it off with a gravity bleed overnight. Also, did you bench bleed the master cylinder before you installed it?

I bench bleed the m/c. Been through 4 qts of brake fluid. Letting it gravity bleed over night now

 

[Maysdad199071]

I had heard that with "ABS" vehicles if the pump gets air in it, they can be a bear to bleed. The "Dealership" had no answers??? Hmm that's odd?? At this point ... you've changed a whole bunch of stuff ... to much too soon. So now even more variables to contend with.

So ... that sucks ... still ... back to basics! It's gotta be something going on??? At this point ... (hope it's not your only vehicle??) I'd go with the "Motive bleeder" fill it up with two or three quarts of brake fluid. Pump it up to 14 lbs (I think that's standard but check for your vehicle.)

So pump it up and grab a "beer" and then do "nothing!" If there are no leaks the gauge should stay at 14 lbs ... if there is a leak ... then the fluid is going somewhere???

Vehicle jacked up in the garage, clean cardboard under each wheel, the Master Cylinder and the ABS Pump. If it's leaking you should be able to see it??

And another place to check is inside the vehicle, where the pedals are look for signs of leaking inside. Oh yeah and be sure and wipe down the area where the MC attaches to the Brake Booster. You want it clean and dry. When you pump up the "Motive" check there first to look for leaks.

Ill try the 14lbs test too. No idea whats going on lmao... Dealership told me to do eveeything i tried. Called them after everything was done and bleed with no luck. Im letting it gravity bleed overnight now. Last thing could it be the vacuum booster that the m c bolts too? But i rhought if thats bad the brakes just stay hard. Idk lol..

 

[Chip18]

Ill try the 14lbs test too. No idea whats going on lmao... Dealership told me to do everything i tried. Called them after everything was done and bleed with no luck. I'm letting it gravity bleed overnight now. Last thing could it be the vacuum booster that the m c bolts too? But i thought if that's bad the brakes just stay hard. Idk lol..

Gravity bleeding ... can't hurt but if there is a leak "somewhere??" I don't think that will find it???

All your gonna do is burn thru brake fluid, I'm gonna "guess" there should be a gasket between the "MC" and the "Brake Booster" did you install it???

Here's a clip on an "issue" with the brake booster.:

But really ... you don't know if the "MC" was ever a problem??? You kinda sorta changed it "anyway" under the "well it must be this theory??" That can get "frustrating and expensive!"

The "Motive" is the only thing I would spend more dollars on. If the gauge will not hold at 14 lbs ... (overnight ... screw it ...just pump it up and walk away!) Then the fluid has to be going somewhere?? If it's not on the ground or in the car (pedal area) ... then it could be leaking into the "Brake Booster??"

 

[iLikeEggs]

Gravity bleeding ... can't hurt but if there is a leak "somewhere??" I don't think that will find it???

All your gonna do is burn thru brake fluid, I'm gonna "guess" there should be a gasket between the "MC" and the "Brake Booster" did you install it???

Here's a clip on an "issue" with the brake booster.:

But really ... you don't know if the "MC" was ever a problem??? You kinda sorta changed it "anyway" under the "well it must be this theory??" That can get "frustrating and expensive!"

The "Motive" is the only thing I would spend more dollars on. If the gauge will not hold at 14 lbs ... (overnight ... screw it ...just pump it up and walk away!) Then the fluid has to be going somewhere?? If it's not on the ground or in the car (pedal area) ... then it could be leaking into the "Brake Booster??"

If there's a leak then it won't gravity bleed.
I still think he's got a chunk of air stuck in there somewhere. If the leak was minuscule and just seepage he would proably still get some pedal. With a larger leak he would have noticed all the brake fluid already.

 

[David A my 99 hoe]

Ive been reading replies on this for the past few days. It sounds like it has air in the lines. Have the best brake padel 99 hoe then I have ever had with any other vehicles ive ever owned even before my rear brake line busted on my way home from work at 12am.

I have never been able to get my hoe brakes to bleed by gravity.

I always have someone press the brake pedal three times and hold it. Then I open the bleeder screw and close it. Then tell them to do it again and bleed each wheel out 5 to 6 times each depending on what the fuild looks like coming out.

Sometimes I even start the vehicle and let it run while bleeding the brakes.

I bleed mine out in this order.....RR, LR, RF, LF.

Also its happen to me once before on this....make sure that the person pumping the brakes knows which pedal they should be pushing. Ive had one person pushing the clutch pedal. Lmao

 

[Chip18]

If there's a leak then it won't gravity bleed.
I still think he's got a chunk of air stuck in there somewhere. If the leak was minuscule and just seepage he would proably still get some pedal. With a larger leak he would have noticed all the brake fluid already.

Oh I don't doubt it ... I don't have the time or patience for the Gravity bleeding thing.

Mosty likely an air bubble is "trapped" in the ABS pump?? I did read many years ago that cold happen and it could be "problematic" to clear?? Still ... there is always "Plan B."

Motive Power Bleeder at 14 psi on the MC and ... a "Mighty Vac" at the bleeder valve. One of these guys:
http://www.harborfreight.com/brake-bleeder-and-vacuum-pump-kit-69328.html

Or yeah the "helper" thing can work also but I tend to work alone.

Still I have to wonder about that "Dealership??"