Rear Center Brake Hose

[JPVortex]

Hey y'all with the front suspension rebuild complete in my 2002 Suburban, I also decided to replace all 5 of the brake hoses on the truck. They were original and the rubber was cracking on every single one. All 4 corners went SUPER easy, about 5-10 minutes per side. Using the trick of using a rod to hold the brake pedal about an inch or two down, I lost almost no fluid in the process. But then, the rear center line struck.... The one that goes from the rear axle all the way up to a place I like to call "neverland", because you're never going to be able to see it and never going to be able to get it with a regular flare nut wrench sitting where it is.

So I did the next obvious thing, I took the bolt for the bracket off and slid the whole thing forward(hose and metal line). This worked! I was able to grab the dismounted bracket with vice grips to hold it, and got the flare nut off. I got the new hose installed on both ends, was NOT fun. This is where I realized I made a fatal error, I removed the bracket from the most insanely tight area that you can get.

There is just absolutely zero chance I get that bracket back up there and lined up with its bolt hole. With myself having fingers that somewhat resemble big sausages(lol), I cannot get my hand in there far enough to line up the bracket and start the bolt.

So where do I go from here? Do I keep struggling with the bracket until my knuckles bleed and I curse like a sailor(again) OR do I submit defeat to the beast of a bracket and zip tie the hose/line somewhere safe. Suggestions are welcome. 10/10 PIA job.

 

[OR VietVet]

For now zip tie it with several of them. Then find a friend with no "sausage fingers" and is mechanically inclined. I have said many times that mechanics have eyes in their fingers. Used those eyes today as a matter of fact.

 

[JPVortex]

For now zip tie it with several of them. Then find a friend with no "sausage fingers" and is mechanically inclined. I have said many times that mechanics have eyes in their fingers. Used those eyes today as a matter of fact.

That is very smart. I'm going to give it on more "good old college try" before I zip tie the crap out of it and call up a smaller fingered friend... lol

I do have a side question, related but unrelated at the same time, that maybe you could help me with. Has to do with the master cylinder.

So keep in mind I haven't bled anything yet, so it has next to no brakes yet. But I noticed something. I go to pump up the pedal and it builds pressure even with air in the lines, starts by going to the floor then pumps up pressure and doesn't. But, I leave it be for around 30 seconds tops and then go to pump the pedal again, and it goes right back to the floor, then I can pump it up to have pressure again. Do you think this is just due to all the air that are trapped in all the lines from replacing all these brake hoses, or think the master cylinder is losing pressure internally? There are absolutely zero external leaks anywhere, and to be honest I'm not sure if it's supposed to hold that pressure for longer, or if it's normal with all the air in the system to lose the pressure I built up by pumping the pedal pretty quickly.

 

[OR VietVet]

Before you keep pump the hell out of the master cylinder, you need to fill the master cylinder and leave the top off of it and open the four corners bleeders. If you have done this already and did not say that, well, don't not say what you have done. Let it gravity feed the fluid and when you get a good flow dribbling out, then shut it down and go to the next corner and open the bleeder. Start at right rear, then left rear, then right front and then left front. If you have an advanced enough scanner, you can activate the abs system and bleed it as well.

Anyway, when you gravity bleed all 4 corners, then start at the right rear and follow the same pattern as above, and use a vacuum pump or bleeder with air compressor to pull the fluid and air out. DO NOT PUMP THE MASTER CYLINDER. Hopefully it is not damaged from all the pumping you did. Have a helper put a piece of 2" x 4" so the pedal does not go to the floor. Do not push all the way down and just push once and then let up and then apply slight pressure and open bleeder. While they are slightly pushing, close the bleeder. They should NEVER let up on pedal while the bleeder is open.

There are different forms of what I just said at you tube and watch a few videos to get the idea.

 

[JPVortex]

Before you keep pump the hell out of the master cylinder, you need to fill the master cylinder and leave the top off of it and open the four corners bleeders. If you have done this already and did not say that, well, don't not say what you have done. Let it gravity feed the fluid and when you get a good flow dribbling out, then shut it down and go to the next corner and open the bleeder. Start at right rear, then left rear, then right front and then left front. If you have an advanced enough scanner, you can activate the abs system and bleed it as well.

Anyway, when you gravity bleed all 4 corners, then start at the right rear and follow the same pattern as above, and use a vacuum pump or bleeder with air compressor to pull the fluid and air out. DO NOT PUMP THE MASTER CYLINDER. Hopefully it is not damaged from all the pumping you did. Have a helper put a piece of 2" x 4" so the pedal does not go to the floor. Do not push all the way down and just push once and then let up and then apply slight pressure and open bleeder. While they are slightly pushing, close the bleeder. They should NEVER let up on pedal while the bleeder is open.

There are different forms of what I just said at you tube and watch a few videos to get the idea.

The master cylinder was never emptied at all, has been full the whole time.

When replacing the hoses I kept the pedal pushed part-way down with a prop rod against the seat, which kept the fluid loss at an absolute minimum, only fluid I lost was the fluid in the lines at the time I cracked them open. This kept me from having to deal with bench bleeding the master, and also kept the seals wet, it never went dry at all. So I don't see how I could damage the master cylinder in anyway.

I haven't done any bleeding on the lines yet, all did was pump the brake pedal to pressurize the system some, so I can check for leaks at all the hoses I replaced. I just noticed that it would pump up and make pressure, then I'd leave and come back 30 seconds later and the pressure didn't hold at all, I had to pump it up again.

Why do you recommend not pumping on the brake pedal to bleed the lines out? Are you recommending I use a vacuum or pressure bleeder instead of the traditional 2 person method? I'm a bit confused there.

Thanks!

 

[Fless]

Don't push the brake pedal to the floor. The master cylinder seals have stopped at a certain point over the years, and taking the piston past that point can ruin the seals. One way to avoid this is to put a 2x4 or something else on the floorboard under the pedal to restrict its travel.

 

[JPVortex]

Don't push the brake pedal to the floor. The master cylinder seals have stopped at a certain point over the years, and taking the piston past that point can ruin the seals. One way to avoid this is to put a 2x4 or something else on the floorboard under the pedal to restrict its travel.

hopefully I didn’t cause a problem with the master cylinder. I have never had a problem on other vehicles pushing the pedal to the floor to bleed though, I will say that. The master cylinder has seemed strong to me aswell. Always had good pressure before I did this work and no leaks between the master cylinder and the booster, and I don’t think there’s any internal leaks or else the pedal wouldn’t feel right, and it’s always felt fine.

 

[OR VietVet]

The gravity bleed I am talking about is to help remove the air in the system. You will still likely have some air after that is done but the gravity bleed/drip helps get the air out before a bleeding process starts. I always like a vacuum pull of brake fluid/air when bleeding. IMO, is the best way to get air out. The gravity bleed will shorten the time it takes to do that.

If you push slightly and get pressure, hold it and crack the lines at the master cylinder and look for bubbles or solid fluid. DO NOT push ******* that pedal while doing this. Just slight pressure and do not release the pedal while lines are open. Then fill and do the gravity bleed.

Like I said, watch a few videos. Seeing is sometimes better than trying to read and remember.

 

[JPVortex]

The gravity bleed I am talking about is to help remove the air in the system. You will still likely have some air after that is done but the gravity bleed/drip helps get the air out before a bleeding process starts. I always like a vacuum pull of brake fluid/air when bleeding. IMO, is the best way to get air out. The gravity bleed will shorten the time it takes to do that.

If you push slightly and get pressure, hold it and crack the lines at the master cylinder and look for bubbles or solid fluid. DO NOT push ******* that pedal while doing this. Just slight pressure and do not release the pedal while lines are open. Then fill and do the gravity bleed.

Like I said, watch a few videos. Seeing is sometimes better than trying to read and remember.

Well yeah I know how to bleed brakes, I usually gravity bleed a bit to start(usually doesn't do a whole lot) then just use the simple 2 person method though. One person in the truck holds the pedal down, and I crack the bleeder let fluid/air come out, close the bleeder and have them release the pedal, then repeat till all air is out of the line, and move onto the next side(in the proper order farthest-closest to MC.)

 

[JPVortex]

having a real PIA bleeding the suburbans brakes right now, just doing the rears now. I bled the rear passenger, went fine, there was actually almost no air at all in it. Went to the drivers rear and I cannot get air to stop coming out with the fluid, no matter what. The MC was never emptied or anything, so I don't really think that the ABS module would get air in it? What yall think? I have a buddy who's scanner I can borrow to try and cycle the ABS pump, just thinking if it's worth it.

Hopefully I didnt damage the MC

 

[rockola1971]

having a real PIA bleeding the suburbans brakes right now, just doing the rears now. I bled the rear passenger, went fine, there was actually almost no air at all in it. Went to the drivers rear and I cannot get air to stop coming out with the fluid, no matter what. The MC was never emptied or anything, so I don't really think that the ABS module would get air in it? What yall think? I have a buddy who's scanner I can borrow to try and cycle the ABS pump, just thinking if it's worth it.

Hopefully I didnt damage the MC

If you are getting pressure buildup at the brake pedal then you likely didnt trash the MC. Typically when someone pushes the MC seals past the long term use wear point there is no coming back from that and the MC will never build any pressure up at all.

You my friend have air trapped and will never get it out without that buddies scanner that will hopefully have the auto bleed feature of cycling the ABS pump and solenoids. Dont be surprised if you have to run the auto bleed 7-10 times because of how many lines you had to replace. Its just the nature of the beast. Once you embrace it, it gets easy and ends up with a very firm brake pedal for our generation that is known to be much less firmer than the 07+.

 

[JPVortex]

If you are getting pressure buildup at the brake pedal then you likely didnt trash the MC. Typically when someone pushes the MC seals past the long term use wear point there is no coming back from that and the MC will never build any pressure up at all.

You my friend have air trapped and will never get it out without that buddies scanner that will hopefully have the auto bleed feature of cycling the ABS pump and solenoids. Dont be surprised if you have to run the auto bleed 7-10 times because of how many lines you had to replace. Its just the nature of the beast. Once you embrace it, it gets easy and ends up with a very firm brake pedal for our generation that is known to be much less firmer than the 07+.

Thank you! Yeah the master cylinder still builds up great pressure.

Unfortunately I borrowed my friends scan tool…. And the firmware version is too old and doesn’t have the abs bleed option yet. I tried updating it but it’s bound to his account on the computer and he can’t remember the login.

So I did the right thing and went ahead and ordered the cheapest scan tool that can do an abs bleed. It’s a $115 Foxwell scanner. Should be here next week!

You think I should run the pump 10 times before I bleed them again at all? Or start with like just a few cycles, like 2 or 3?

 

[rockola1971]

Thank you! Yeah the master cylinder still builds up great pressure.

Unfortunately I borrowed my friends scan tool…. And the firmware version is too old and doesn’t have the abs bleed option yet. I tried updating it but it’s bound to his account on the computer and he can’t remember the login.

So I did the right thing and went ahead and ordered the cheapest scan tool that can do an abs bleed. It’s a $115 Foxwell scanner. Should be here next week!

You think I should run the pump 10 times before I bleed them again at all? Or start with like just a few cycles, like 2 or 3?

Im not sure what you are asking in your last sentence. It appears that you arent familiar with the auto bleed procedure. During the procedure the scan tool operates the ABS pump and cycles the specific solenoids at the PROPER TIME. All you have to do is follow the instructions on which wheel to be at and it will tell you when to crack bleeder open and then close it.

 

[JPVortex]

Im not sure what you are asking in your last sentence. It appears that you arent familiar with the auto bleed procedure. During the procedure the scan tool operates the ABS pump and cycles the specific solenoids at the PROPER TIME. All you have to do is follow the instructions on which wheel to be at and it will tell you when to crack bleeder open and then close it.

Yeah I know what you’re talking about, but that only seems to be the case on the really more expensive scanners.

On the cheaper ones with the “auto bleed” all they seem to do is run the abs pump, they don’t actually bring you through a specific procedure like the more expensive tools.

 

[OR VietVet]

Yeah I know what you’re talking about, but that only seems to be the case on the really more expensive scanners.

On the cheaper ones with the “auto bleed” all they seem to do is run the abs pump, they don’t actually bring you through a specific procedure like the more expensive tools.

What Foxwell scanner did you order?

 

[JPVortex]

What Foxwell scanner did you order?

I ordered a Foxwell NT630 Plus. Upon further investigation, seems this scanner may actually have a true abs auto bleed sequence, where it guides you through opening bleeders, and opens specific valves. Will definitely found out once it comes in though! Lol.

 

[JPVortex]

So I’m guessing before I even attempt this abs bleed I should manually bleed all 4 corners first and get as much air as possible? Obviously I’m not going to get all the air from the rear left, but I’m thinking if I get all the air I can on each side it’d make abs bleeding way easier.

 

[JPVortex]

So folks, little update, I don't think theres any air in the ABS pump and reason is, I have found a leak. But it's one of 2 possibilities.

It's leaking from where the rear center brake hose and the left hard line with a flare fitting bolt up to each other. I pump the pedal and come back and see it dripping down the metal line(not a lot, but enough to cause air bubbles!). Question is, I have no clue if it's the male hard line side thats causing the leak or the female side on the rubber hose that's causing it. It's tight aswell.... I will pull the steel line off and see how the flare looks, and go from there!

 

[JPVortex]

Think I'm going to start with the metal line, pulled the fitting off, and the flare looks slightly crooked. May be enough to cause the leak.

 

[JPVortex]

Was indeed the hard line. Replaced with a pre-flared autozone line and no leaks! Will update with bleeding results tomorrow.