Hydro boost question

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Chevy_Monster

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Have a quick question. I have an 05 suburban I just picked up. Brake pedal goes to the floor. I have replaced the abs module which was bad, I replaced the master cylinder which was also bad. The pedal still goes to the floor after I start the truck. Would a bad hydro booster cause the pedal to go to the floor? The truck will stop with like 1% brakes if the pedal goes all the way to the floor.

I did bench bleed the master cylinder and made sure all air was bleed out.

All opinions are welcome. I still also have the abs light on and traction control light on which I need to figure out.
 
How did you bleed the ABS system, you had a way of commanding it to open to permit bleeding the whole brake system?
 
zora said:
How did you bleed the ABS system, you had a way of commanding it to open to permit bleeding the whole brake system?
Click to expand...
Here is what's weird. It's telling me abs bleed is not supported on my scanner. So I haven't been able to do a bleed from the scanner
 
Than start with that step, not sure if you can find a rental scanner, before replacing more parts.
 
zora said:
Than start with that step, not sure if you can find a rental scanner, before replacing more parts.
Click to expand...
So as an update. I went back to the abs module. I undid the wire harness and pushed it back on. The plug uses a reverse locking handle of sorts. I can push it down most of the way but hit resistance. It won't click all the way down for some reason. ABS light went off.

Now getting C0279. Apparently a precharge pump error. Is there a ground for it I can check? I checked the grounding for the abs module and that was all corroded
 
Read post 2, I know different Chevrolet

WTF is this code and how do I fix it

2003 Yukon Denali throwing a C0279 code and because of this I can't bleed my abs module and have zero brakes
www.tahoeyukonforum.com www.tahoeyukonforum.com
 
zora said:
Read post 2, I know different Chevrolet

WTF is this code and how do I fix it

2003 Yukon Denali throwing a C0279 code and because of this I can't bleed my abs module and have zero brakes
www.tahoeyukonforum.com www.tahoeyukonforum.com
Click to expand...
So I found the diagnostic sheet in my 9,427.6 pg service manual for it. I first measured it at zero ohms. When I went and measured where the wire harness meets the pump I measured 2.6 ohms. Manual and the forum link both said that if it measures outside of around 1ohm it's bad. So Napa naturally doesn't have it in their system so will have to order one off the internet. Quite possibly the evil bay. So I will order one and get it shipped and will post another update again when I get it.
 
Chevy_Monster said:
So I found the diagnostic sheet in my 9,427.6 pg service manual for it. I first measured it at zero ohms. When I went and measured where the wire harness meets the pump I measured 2.6 ohms. Manual and the forum link both said that if it measures outside of around 1ohm it's bad. So Napa naturally doesn't have it in their system so will have to order one off the internet. Quite possibly the evil bay. So I will order one and get it shipped and will post another update again when I get it.
Click to expand...
Only thing I wish I had more out of curiosity is an actual flow diagram of how the precharge pump actually works with the abs and hydro pump. Service manual says when the precharge pump fails that you automatically have to replace the abs module which I'm curious why? Both my module and precharge pump were bad so it didn't matter anyway.
 
Chevy_Monster said:
So I found the diagnostic sheet in my 9,427.6 pg service manual for it. I first measured it at zero ohms. When I went and measured where the wire harness meets the pump I measured 2.6 ohms. Manual and the forum link both said that if it measures outside of around 1ohm it's bad. So Napa naturally doesn't have it in their system so will have to order one off the internet. Quite possibly the evil bay. So I will order one and get it shipped and will post another update again when I get it.
Click to expand...
Chevy_Monster said:
Is that precharge pump in the engine bay? It looks like the rear of firewall or am I wrong?
Click to expand...
So I changed the precharge pump and abs light came back on. No brakes. Looks like back to the drawing board
 
do you have a code reader capable or reading ABS?
 
zora said:
do you have a code reader capable or reading ABS?
Click to expand...
Yes and it said ABS not an option basically. I don't think it's communicating with the abs again.
It's a Zurich I just bought from harbor freight. Fully bidirectional. ZR15S
 
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