Help, pulling hard left under brakes.

[Lewo68]

Hi, I have a 97 express G3500 that is mostly standard. Under brakes it has started to pull left. I cannot figure out why. The left hand front brake is working far better than the right. I have bleed both sides and have not found any air in the system. The pads and discs look fine. When bleeding at the calipers the left vents a large amount of oil with light resistance on the pedal, the right side by comparison vents less oil with more resistance at the pedal and pushes down slower. Cracking and bleeding the system at the ABS motor has similiar results as the calipers with less oil flow and more resistance on the right hand side. The master cylinder appears fine and cracking the fitting down at the ABS motor confirms this. It seems to me that the ABS motor is restricting oil to the right line and caliper. Why?
The right front brake does work and with enough pressure will lock up, it just responds slower and is less powerful than the left.
Since I have owned this van the ABS has never worked and that is fine with me. I am in Australia and the vehicle is rare over here, my mechanic has been helpful but is not familiar with this system and the parts used. After surfing the net yesterday I found and bled a valve on the side of the ABS motor, facing the centreline of the van. Is there another facing outwards towards the side? I found a rubber cap but it doesn`t appear to have the same valve installed, it sits close to the sill and is hard to get a good look. I am stumped, any help or advise greatly appreciated.

 

[Jeff Janssen]

IF your flex lines are old they may be collapsing internally under pressure/the inner liner develops a leak and impedes the flow. It's a fairly cheap fix to replace them, especially if they are original.

 

[Lewo68]

Thanks, I don`t think the flex lines are the problem as I have cracked the fitting on the chassis where the flex line joins the steel and the low oil flow, pressure/ resistance issue remains the same as it is at the ABS motor fittings. I had considered it though.

 

[SUBURBAN5]

What happens if you pull the abs fuse and try to stop again? Does it still pull?

 

[someotherguy]

The flex hoses are the #1 cause of this symptom, so you can ignore that advice at your own risk.

They do go bad. Some of them even went bad when the trucks were still new - my previous '94 had them replaced by the dealer under warranty (was included with paperwork when I bought it from the original owner.)

Richard

 

[SUBURBAN5]

The flex hoses are the #1 cause of this symptom, so you can ignore that advice at your own risk.

They do go bad. Some of them even went bad when the trucks were still new - my previous '94 had them replaced by the dealer under warranty (was included with paperwork when I bought it from the original owner.)

Richard

That's why I'm trying ss braided lol

You must be registered for see images attach

 

[someotherguy]

Biggest advantage to the braided stainless lines is that they're new. Beyond that, we would hope they'll last longer than the originals. Jury's out as I don't know anyone yet that has had a set installed longer than most of the OEM hoses out there.

Richard

 

[Lewo68]

OK, will revisit the flex line to the right hand caliper. As for the ABS fuse, it may have been previously removed as the ABS has never worked and I have have only realized that it is fitted while trying to solve this issue, something else to look at. Thanks

 

[RichLo]

x2 on the berake lines

also have you taken your calipers off and cleaned and greased the sliders?

 

[Lewo68]

Out of action for the weekend. Had the discs machined and new pads fitted maybe a year or so ago. Haven`t been in there since. Will check this also.