Impossible to bleed brakes

[454cid]

That doesn't look right. Here is mine with all kinds of room for the suspension to cycle.

You must be registered for see images attach

 

[Coroner81]

Our brackets look different. Mine is bolted into the crossmember the tank straps go into. I thought this hose looked shorter than the stock hose when I replaced it last year.

I'll see what I can get my hands on. If the new one is short, I'll make a new bracket to give it more travel space.

 

[east302]

2 quarts through each rear wheel, and not a goddamn thing changed.

Fronts bled fine. If I can find enough F's to give, Ill try replacing the rear hose this weekend. It looks like it should be a little longer. (That's what she said) After that I quit.

You must be registered for see images attach

Is that wet from a penetrating oil? Meaning...if you had a small leak would you be able to spot it?


Sent from my iPhone using Tapatalk

 

[454cid]

I just looked up parts on Rockauto, and new lines are less than 18" for a Tahoe or truck. I think something has been changed on your Tahoe, like maybe someone grabbed some old bracket they had lying around and used it. I looked at my dad's old c1500 and it's similar to my truck.

You must be registered for see images attach

 

[Coroner81]

Is that wet from a penetrating oil? Meaning...if you had a small leak would you be able to spot it?

It was initially dry, and is now wet from brake fluid. I replaced both lines on the rear axle the other day, and just took everything apart today to clean up the fittings, flares, etc..

I just looked up parts on Rockauto, and new lines are less than 18" for a Tahoe or truck. I think something has been changed on your Tahoe, like maybe someone grabbed some old bracket they had lying around and used it. I looked at my dad's old c1500 and it's similar to my truck.

You must be registered for see images attach

The weather should be decent tomorrow, so I'll take a few pictures while I disassemble everything again. I'll take a few pictures of the bracket, where it's mounted, etc.. It has the notches in the hole to center the hose, and has one of those tabs that slips into a hole on the crossmember to keep it oriented correctly while tightening it. I have no doubt that it's an OEM part, the question is from what vehicle.. Maybe it'll help someone else in the future.

 

[letitsnow]

When I replaced all brake lines & proportioning valve on my '99, I use just a bit over 1 quart of brake fluid to bleed to all 4 wheels. Something is wrong. I would try a different master cylinder. If you had a leak anywhere that was allowing air in, you'd see mucho brake fluid dripping from that leak.

I bled my brakes by myself - just by opening one bleeder at a time, and letting gravity do its thing.

 

[Coroner81]

When I replaced all brake lines & proportioning valve on my '99, I use just a bit over 1 quart of brake fluid to bleed to all 4 wheels. Something is wrong. I would try a different master cylinder. If you had a leak anywhere that was allowing air in, you'd see mucho brake fluid dripping from that leak.

I bled my brakes by myself - just by opening one bleeder at a time, and letting gravity do its thing.

I know something is wrong lol. I couldn't even guess how many quarts I've run through trying to get this fixed. Every time I changed something I'd bleed them all again.

The MC is fine. When I block off the outlets, the brake pedal is solid, no fade, no problems.
I thought the same thing about the leak, except there was no fluid dripping, and none of the fittings were wet. Your guess is as good as mine on that one. I've seen discussions where people say air molecules are smaller, and can leak out while hydraulic fluid doesn't leak, but who knows.

I'm not a fan of gravity bleeding. I question its effectiveness, especially on a vehicle with ABS. I also don't have the attention span to wait that out and keep filling the MC. I find it's easier to bleed under pressure, or vacuum.

 

[east302]

With the MC ports plugged, did the pedal eventually start to sink or was it firm for a good while?

Assuming it held the entire time, I’d use some hose clamp pliers to pinch both rear hoses and see if it firms up. Could be a hose expanding or maybe a cylinder extending too far?

This is a long shot, but may be worth looking at this video. Somewhere in the back of my mind I remember someone having a soft pedal that was remedied this way.

xc_hide_links_from_guests_guests_error_hide_media

Sent from my iPhone using Tapatalk

 

[letitsnow]

Not trying to be a dick, but, my brakes work and yours don't. I'd try gravity bleeding it, especially since you said that you have removed the abs...

It is a very simple system once the abs is removed. Either you aren't good at bleeding brakes, or you have another bad master cylinder. Gravity bleeding will at least eliminate option 1.

If there are no leaks and no abs - The master is the only place that can allow air to enter.

 

[letitsnow]

2 pf my bleeder screws were corroded, and didn't seal completely when tightening. Didn't notice that right away because everything was wet from bleeding. That could possibly allow air back in while bleeding.