Brake Bleed Issue Advice

[EBranger96]

Hi guys, 1990 2.9L 6 cyl here. I was performing a routine brake bleed and flush and an issue came up with my back left wheel. That wheel simply will not bleed - I completely removed the bleed bolt and cleaned it (it’s not the issue). Even after removing the bleed bolt and vigorously pumping the brakes, I couldn’t get brake fluid to show up. Any advice on how to continue root causing the issue / possible causes?

 

[Sharky]

trace the upstream flow, the line or hose to that brake cylinder is blocked or pinched. maybe at a junction block, that line is not getting fluid ?

 

[sgtsandman]

The rubber brake hose could have failed internally. People have run into that before.

 

[55trucker]

Do you have pressure to the opposite side? , the wheel cylinder at that corner may be completely corroded inside due to moisture. Remove the line to the cylinder & try pushing fluid to it again.

 

[EBranger96]

Do you have pressure to the opposite side? , the wheel cylinder at that corner may be completely corroded inside due to moisture. Remove the line to the cylinder & try pushing fluid to it again.

There is pressure to all three other tires, although it isnt as strong as I'd expected it to be. I think I'll do that - remove the line to the cylinder and pump / trace the line to the defective wheel

 

[55trucker]

Given where you live that area would be consider a high humidity area, not knowing what the history of the vehicle is...has the fluid seen a flush on a regular basis?
Most brake fluids should be flushed on a 36 mth basis, some manufacturers even recommend more often, the higher the humidity the more frequently it should be changed as brake fluid is hygroscopic (absorbs moisture).

 

[EBranger96]

Unfortunately I think the truck has seen its fair share of neglect - I just recently purchased it and the first thing I did was bleed and flush the brakes. The fluid was pretty much black and had some small particulates. Moisture might be the main cause here. I'll keep y'all posted

 

[EBranger96]

I’ve traced the line back to the ABS hydraulics module. There flow above it and no flow out of it. Stomped on the brakes and saw no brake fluid coming out. Do I need to replace the unit?

 

[sgtsandman]

If there isn't any flow coming out of the module, then yes.

 

[EBranger96]

Just replaced the module and I got flow back to the rear Bunch of crap stuck in them probably from the master, now time to replace the wheel cylinder