brake problems

cat345

New member
Sep 25, 2019
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hello everyone! new member here from Washington. sorry in advance for the long read I like being thourough when I can.

I have a 2008 gmc 2500 short bed four door. Its all deleted, lift pump, down pipe, rail plug, sump, all the basics. 180k

I noticed ohhhhh about 2 years ago that my master cylinder was leaky or the hydro boost it was hard to tell. I did like most guys would and "kept an eye on it" hardly used any fluid I added a splash like once.

so short time after that maybe 6 months a caliper stuck in the back driver side and chewed up the rotor pretty good. I tore it aprt and to my surprise the other three corners were not effected at all i didnt even have to change the pads. so i replaced that one side new rotor, new caliper, and pads. i pulled the booster apart and couldnt figure out why it was leaking but found out it was leaking out of what looks like a weep hole between the master and hydro boost.

full disclosure- I had no idea at the time what this things job was other then "boost" my brakes, i had no idea it was apart of the steering pump system. so i tossed it back together with some good old glue. Yeah you read that right i glued the shit out of the master and hydro boost to try and limp this thing. I have 3 kids and winters are slow so sometimes you rig stuff.

so truck ran great for like 6 months after that not an issue and my glue job held up for quite awhile too until the first time i really had to get on the brakes. Since then job got better, make more money, and company truck so this beauty has been parked for awhile now but now i have the time and money to get her back to former glory. unfortunately it started to chew another rotor up this time the passenger front a couple months back and has sat since.

Im not sure if the hydro boost is connected to the calipers or not but i went and bought a new hydro boost, two new napas finest calipers for the front, two napa fleet rotors for the front, and napa fleet pads for all four corners, aaaand wheel bearings for the front. I didnt get rotors or calipers for the rear because the one side like i said is pretty much brand new and shows no wear and same with the other side im just doing pads for good measure. and again this go around the other three corners were not really effected besides the driver front rotor had some heat spots and possibly cracks.

So I think its fair to say i have a messed up master/booster and some funky pressures going on. I think the calipers were just old and stuck because the crazy pressures coming from the booster but they could be related more internally then that.

Anyways i installed everything i mentioned including switching out the plunger deal, spring, and retainer that goes between the master and booster since the new booster does not come with these. Everything is down to tq spec and i have triple checked almost everything.


I followwed the instructions to the booster to a T as well as watching some you tube vids on it while doing it. I added fluid to the steering rez and started it worked the tires back and forth shut it off filled the rez and repeat until the level in the steering was perfect.


Heres my issue, I am not getting any fluid at all from the front calipers thay have not even pumped out at all onto the new rotors and pads. The back calipers spit fluid at first and i think thats just what was left over in the calipers since i never broke those lines loose until bleeding time.


I did not replace the master cylinder just the booster so i find myself with two possible issues. 1. when i installed the plunger, spring, and retainer maybe it got all messed up when i first applied the petal or 2. this is probably the original master and maybe its all gummed up in there and the rod got stuck??? because im getting no fluid at all at any corner and no matter how i pump the brakes truck on or off the petal hits the ground and comes back kind of slow. Idk im at a loss everyone i do think my issue lies within the master either its bad or i installed the plunger thing wonky. what do you guys think???? im going to split the master tomorrow morning and see what position that plunger is in. any help is really appricated.
 

snowman22

Member
Jan 30, 2018
298
8
18
SoCal
Do you have access to a Tech2? With a caliper change on the front I imagine you could have air in the lines/abs motor and need to bleed it out. Do you have a vacuum bleeder or are you just trying to apply pedal pressure and crack the bleeder? I could be wrong, but I don't see the hydroboost system stopping you from getting a good bleed on the brakes, so I doubt that's your issue.
 

ikeG

Oughta Know Better
Apr 19, 2011
2,428
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63
Western PA
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Need to cycle the valving in the abs module before getting too much more involved. Scan tool is the only way if you have no brakes.
Also, might be a good time to replace your brake hoses. The fronts particularly. The brackets that encase the hose rust, restricting the hose inside diameter.

Sent from my SM-G960U using Tapatalk
 

Benny315

Benny
Feb 11, 2019
86
3
8
Backwoods, Savannah, NY
Just keep working at it, they will bleed eventually. Check to make sure you didn't twist/kink the front hose when you put them on and also that they are not collapsed. I have a tech-2 but have never needed it even with all new lines installed. Having a friend in the cab helps save some time.
 

cat345

New member
Sep 25, 2019
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Do you have access to a Tech2? With a caliper change on the front I imagine you could have air in the lines/abs motor and need to bleed it out. Do you have a vacuum bleeder or are you just trying to apply pedal pressure and crack the bleeder? I could be wrong, but I don't see the hydroboost system stopping you from getting a good bleed on the brakes, so I doubt that's your issue.

I don’t have a tech 2 but I did go and buy a do it yourself vacuum bleeder I should have said that in the OP. I’ve tried everything I can think of pumping these bad boys and using the tool. And I agree I don’t think the hydro is the issue I intsalled it perfectly and bled it.
 

cat345

New member
Sep 25, 2019
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Just keep working at it, they will bleed eventually. Check to make sure you didn't twist/kink the front hose when you put them on and also that they are not collapsed. I have a tech-2 but have never needed it even with all new lines installed. Having a friend in the cab helps save some time.

I was under it awhile and I’m not getting anything at all to come out of any caliper it’s not even taking fluid from the Rez It’s like something is plugged. I had my wife helping me at first pumping the brakes and then I went and bought a vacuum brake bleeder and tried that. Nothing. No lines are pinched nothing really changed I took off old stuff put new stuff on and triple checked everything I was doing. I will keep at it I guess I don’t have a scan tool or a way to even get it a brake shop.
 

cat345

New member
Sep 25, 2019
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Need to cycle the valving in the abs module before getting too much more involved. Scan tool is the only way if you have no brakes.
Also, might be a good time to replace your brake hoses. The fronts particularly. The brackets that encase the hose rust, restricting the hose inside diameter.

Sent from my SM-G960U using Tapatalk

I will go and check out my hoses again but that was something I looked at pretty extensively yesterday. I even bought the hoses that go from steering pump to hydro boost because I was told to in almost everything I read when researching this and because the return looked a little weathered. The brake lines looked great and I didn’t notice any odd or soft spots that’s stuck out.

This abs module is news to me I don’t have a scanner but I guess that’s an avenue to look into.
 

Benny315

Benny
Feb 11, 2019
86
3
8
Backwoods, Savannah, NY
I don't remember exactly how I got mine, I do recall it being a pain. I pulled the cab stripped the frame and ran all new nickle copper lines, new rear calipers all new pads. It did take me a few nights of trying things to get it.
 

Benny315

Benny
Feb 11, 2019
86
3
8
Backwoods, Savannah, NY
Try to think what I did different. I do most everything myself here so. I may have cracked the bleeders (no foot on the pedal) then push to the floor hold and tighten bleeder back up until fluid comes. Then do pressure build and bleed. I use a stick between the pedal and the seat when I do it alone (is pretty much every time).
 

cat345

New member
Sep 25, 2019
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I don't remember exactly how I got mine, I do recall it being a pain. I pulled the cab stripped the frame and ran all new nickle copper lines, new rear calipers all new pads. It did take me a few nights of trying things to get it.

You pulled the cab!? Oh lord please no. I really hope this isn’t my case the truck has 180xxx on it. I’ve had countless square bodies and old ford pickups and never had to worry about brake line replacement.

What lines did you go with like from Napa or did you order them? Can you order them pre bent? Also is it a bad idea to go with easier to install high pressure soft lines??
 

cat345

New member
Sep 25, 2019
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Try to think what I did different. I do most everything myself here so. I may have cracked the bleeders (no foot on the pedal) then push to the floor hold and tighten bleeder back up until fluid comes. Then do pressure build and bleed. I use a stick between the pedal and the seat when I do it alone (is pretty much every time).

Thank you I will try that today. It’s all been straight forward and easy even the hydro boost install wasn’t bad besides fastening it to the firewall from inside the tru I that kind of sucked.
 

cat345

New member
Sep 25, 2019
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Did you let air get into the master? If you did you will need to do a bench bleed.

Well I’m sure I did I took the master all the way off and cleaned it out then took the booster off and installed the new one. But when I pulled it apart the first time months ago I installed it after not figuring out why it was leaking and had no issues bleeding the brakes. I installed a new caliper then too.

I pretty much did the same thing this time around except 2 calipers instead of one and a new booster. So maybe I do need to bench it but considering I did the same thing before I don’t know why it’s an issue now.
 

Benny315

Benny
Feb 11, 2019
86
3
8
Backwoods, Savannah, NY
I only pulled the cab to sandblast repaint the chassy and do body lift and complete engine/trans swap..lol. My truck was a mess when i got it, but it was a smoking deal. I have another 06 I picked up cheap and going to do the same, ny salt is killer on them. Also did my 1500 years ago, I do remember have issue bleeding them too,, but I got them, no special tools needed.
 

cat345

New member
Sep 25, 2019
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This is more likely your issue if it happened.

Ya I did I guess. I pulled it off completely and cleaned it out good. Installed the hydro boost then reinstalled the master and added fluid. I’ve done this same thing on this same truck before and never needed to do anything other then bleed the four corners. How do you bench bleed?
 

cat345

New member
Sep 25, 2019
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ok so I got an update should have posted 2 weeks ago. My problem was the master cylinder I guess it was all messed up that's why I wasn't getting any fluid to the calipers. replaced that and bam! I was able to bleed all four corners. I didn't need to get a scan tool for the abs.

So I found that I still didn't have the brakes I thought I should when I have replaced, brake master, booster, two front calipers, front rotors, all four corners in pads. Bled the shit out of everything. even bench bled the new master.

Come to find out I got a bad steering pump.

replaced that sob and drove it like 2 blocks after trying and trying to bleed the new pump. seemed ok then got pretty hard to steer again so I pulled over and the fluid level was about the same after I last filled it after the bleed sequence on the new sp.

I was sitting at a gas station trying to fogire out what may have been wrong and started to smell fluid inside the cab bout the second I smelt the fluid I heard a weird noise looked down at my feet and fluid was pissing all over my boots so I turned the truck off immediately. I got out to look up under the dash where it was coming from and for one noticed the petal was sticking out more then it should be and I grabbed it and you could dang near touch the dash with the brake petal. so the plunger attached to the petal had basicially backed out of the inside of the booster and that's where the fluid came rushing in.

truck ran fine for dang near 2 weeks with brakes and steering. I even took 4 trips 2 hours one way hunting, 2 of the 4 with a 6k pound camper behind me. No issues.

so now the truck is on the back of a tow truck going to an actual professional brake place. not sure what I could have messed up or if I just got a weak faulty booster out the box. maybe its karma.