Yea, @Tonyrodz, everyone knows that. Just remember, it is not your money you are spending, it is HIS MONEY you are spending.
New member 2003 Z71 with brake issue
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Yea, @Tonyrodz, everyone knows that. Just remember, it is not your money you are spending, it is HIS MONEY you are spending.
Sounds like air, or possibly soft brake hoses which can swell under pressure. When they bled it, did they have the tool to activate and bleed the ABS pump? Was a power bleeder used?
Some vehicles bleed ok using just the old school method with pumping the pedal, others I’ve had in the shop that require all the tech tools (bidirectional ABS scanner and power bleeder) to get the residual air out.
Some people swap in stainless brake hoses to replace the rubber but that’s usually to get some minor improvement in pedal feel. Based on the severity of your symptoms I’ll place my bet on air that’s never been chased out.
And, sounds stupid, but did they put any calipers on upside down? I have seen left /right get mixed up and the bleeder is not on top.
Some vehicles bleed ok using just the old school method with pumping the pedal, others I’ve had in the shop that require all the tech tools (bidirectional ABS scanner and power bleeder) to get the residual air out.
Some people swap in stainless brake hoses to replace the rubber but that’s usually to get some minor improvement in pedal feel. Based on the severity of your symptoms I’ll place my bet on air that’s never been chased out.
And, sounds stupid, but did they put any calipers on upside down? I have seen left /right get mixed up and the bleeder is not on top.
Calipers are oriented correctly, I bled them myself using the old school method, pumped most of the old fluid out, didn't see much air come out , worked my way from the rear passenger forward. The previous owner mentioned they bled them but I doubt they used any tools to bleed em out.
I'm not so much worried about the costs of doing the conversion, I have just heard mixed results, and have also read that the old vacuum system were repaired to original feel, but also heard of guys throw so much money at parts but never get them to work properly.
Update...so I decided to give the gravel road hard brake deal a try...I definitely, definitely increased stopping power. I'm able to actually stop and lock the brakes a bit. It did not give me a firmer brake pedal, and it still feels spongy a sinks , but I can actually stop now...so what does this tell me? bad ABS ? when I was braking on dirt, felt all kinds things going on with the pedal, so I am getting some ABS action, but the ABS lights did not come on.
I recall on my 05 z71 suburban, the ABS lights came one once in the rain when I hit some pot holes.
I recall on my 05 z71 suburban, the ABS lights came one once in the rain when I hit some pot holes.
Sounds like you have air in the system near the ABS pump and it expelled some when you forced the pump to activate on the gravel.
If it were mine, I’d take it to a shop with the right tools to force the pump on and power bleed it. Maybe even the dealer if there’s one you trust.
I am a hard core DIY guy however sometimes the pros have tools I can’t or won’t buy.
If it were mine, I’d take it to a shop with the right tools to force the pump on and power bleed it. Maybe even the dealer if there’s one you trust.
I am a hard core DIY guy however sometimes the pros have tools I can’t or won’t buy.
George B
¯\_(ツ)_/¯
Same results as me with my 03. I ended up with a new master and several bleeding events while cycling the ABS in between. Autel makes a handheld that will do the ABS cycle for you and a Chinese TechII will do it too. The motive Power bleeder is a great tool as well.
In the end my brakes still sucked. I don't have any more data since I traded that truck for my 13 Burb.
So sitting over night, the brakes reverted back to horrible. The frustrating part is every shop I got too, they seem not to want to touch this thing, there are no codes being thrown. So my only option seems to be to tell Them what I want done.
ThisIsLivin
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I had the same thing happen over time on my 03 Suburban. I am sure it's either air in the ABS or the ABS itself. Mine has 360k on it and the lines are rusted so I am planning on a complete replacement of everything from the master cylinder out. I've already replaced the master cylinder twice and pumped a gallon of fluid through the lines. I plan on plumbing around the ABS as it's not worth replacing.
If the shops you are taking it to don't want to do what you are asking I wouldn't trust them to change my oil. Find a reputable shop that will listen to an educated owner. My 2c's ... it sounds like you definitely have air trapped in the system, likely in the ABS module loops. The only way to get this out is with the scanner tool that can activate the bleed cycle function. I would try to find a shop that will do this first before going to all the trouble of replacing the booster. If it doesn't work you're not going to be out much and you've also found the shop to do a full system bleed after you replace all the hydroboost components.
From what I've seen, bleeding antilock on gm takes 2 qts. or way more than 1 qt. Everybody stops early, so air still in there. ( it takes about 3 brake pushes to get a known bubble out back, so a little insurance is alot of pumping).
The other thing that helps, 2 man bleeding or pressure bleeding is to cycle the key on off several times with foot on pedal(2man) . Done that a few times now and bleeding finishes faster (activates ABS solenoid self test). I don't remember who on this board suggested that, but it works well and I thank you. Newer models may not work cycling key. Using Tech2 (vxdiag)now.
Also mentioned above is caliper hoses, They are cheap and not a bad Idea every 100K.
The other thing that helps, 2 man bleeding or pressure bleeding is to cycle the key on off several times with foot on pedal(2man) . Done that a few times now and bleeding finishes faster (activates ABS solenoid self test). I don't remember who on this board suggested that, but it works well and I thank you. Newer models may not work cycling key. Using Tech2 (vxdiag)now.
Also mentioned above is caliper hoses, They are cheap and not a bad Idea every 100K.
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