Brake System Flush

[pdxrealtor]

Originally Posted by Hellz

it is pretty simple actually. the bleed valves are self bleeding.

1. i flushed out my system about a month ago. i completely drained the whole system.
2.filled resivoir
3. attached a tube over the bleed valve and ran to a bucket.
4. started the engine and pumped brakes until fluid came out of tube in to bucket.
5. refilled resi. and moved to next brake repeatign the process above.

when pumping the brakes, i actually could get on my knees and use my hand to pump the brake while watching under the vehicle for fluid to come out.

with the self bleeders, it is a very simple process.. alot better than a 2 man job and having to screw with the beed vavle after every pump.

Huh?? Let me get this straight. Those bleeder valves are one way only? They let air out but not in?? I've never heard of that....

I bought the little 'one man' bleeder kit but if it's really not needed I'll take it back.

[Hellz]

ya, they are self bleeding.
you will still need to put a wrench on them to open them up, but it is like only a 1/4 to 1/2 a turn. put a tube on it and pump the brake till its just all fluid. then tighten it up to close off the valve.

so here is an edit to clarify the steps above.

3. loosen the bleeder valve 1/4 to 1/2 a turn then attached a tube over the bleed valve and run to a bucket.

obviously you will want to tighten the valve when done. might sure it is nice and tight.


i bought a couple bottles of fluid, so i went pretty heavy on bleeding the fluid come out. i also wanted to make sure i flushed out whatever was left in after i drained it.


i would return the kit you bought, and spend like $1 on tubing (forgot the size) if it will fit over a zerk fitting, it will fit on the valve.

i picked up 2 ft worth, but only needed about 1ft to the bucket.. i cut it short so i could watch the fluid coming out. this is just a standard air vacuum hose/tubing.
didnt need anythign fancy, just needed something so it wouldnt cause a mess on the ground, and allowed me to collect all the fluid in the bucket. if you dont use a tube or hose, it will get very messy, and make it difficult to watch the bleeding. if you had the choice, pick up clear tubing to make it simplier.

[Hellz]

i had orignally planned on buying the same kit.. then saw the auto parts store had self bleeders, but they didnt have any for the H2.

later i looked in the manual, and it said they are self bleeding valves. so it actually made my day.

[pdxrealtor]

That's great news!

Is there any way to verify the self bleed part without watching the valve itself? I'd hate to be sucking air in the system all the while thinking i'm flushing.

Once air hits the ABS module it's dealer time...

[Hellz]

well you are going to want to watch it for when fluid comes out.

this basically just turns this from a 2 person job to a 1 person.. thats all. you will still need to watch and listen. if you are using a tube, it will sound like sucking soda up in a straw when there is only a little left at the bottom of the cup.
you should be able to see it as well if the tube is clear.

dont get the impression you can loosen the valve, hook the tube up and pump the brakes a few times and be done. while you might be able to do that..its best to watch the fluid come out. if its coming out in spurts, or bubblely, there is still air int he system, and you need to keep pumping. when it starts coming out solid fluid every pump, then your good to close the valve off.

now, if you are getting a sucking in sound as it is sucking in air.. tighten the valve a little until it goes away when you pump. you only have to open the vavle a little to open it up.

you most likely will end up just like me when i did mine. kneeling outside the vehicle and pumping the brakes while watching the fluid come out under the vehicle. im not saying there isnt a better way.. im just saying this is the way that worked for me, and i am able to be confident that the system got bled properly.

[pdxrealtor]

Well to make sure I have these speed bleeder valves I tried this method on the front driver side caliper so I could see what was going on.

I zip tied a clear hose on the bleeder, opened it up, pumped the pedal but it seemed the bubbles would get sucked back into the valve.

I was nervous about my specific truck not having the speed bleeder valves and it seemed to be sucking the fluid and air in as fast as it was coming out.

I ended up using the one man bleeder kit I bought. Actually, I used the one piece that makes it the one man bleeder, the plastic cone shaped piece that fits in the orifice of the bleeder valve.

Anyways.. ran the clear tube attached to the plastic cone piece into a two liter bottle.

Fluid and air would suck up the tube when the break pedal came up from bottomed out, but the bubbles would never get past half way up the tube.

Maybe my truck does have the speed bleeders and I was just too nervous, but I swear those bubbles were sucking right back in that bleeder valve when I tried it out.

Anyways.... drained the master cylinder reservoir, filled it with almost a quart. I flushed that threw the brake lines until MC was almost empty.

Then I put the rest of the quart in to mix up with the still nasty fluid in the MC (the little I couldn't suck out the first time mixed with the new stuff and contaminated it). Then sucked it out.

Dumped in another quart and continued to flush it through the lines. Ended up needing another little bottle of fluid with a few drops to spare. Everything is crystal clear now.

Took on a drive and at first the brakes seemed soft at the top stroke, but when getting on them at 20-25 mph they felt great. At a stop I depressed the pedal to the floor a few times, then while going 20-25 got on em' again real good.

I don't know if things just had to warm up or what but they're firmed up real nice. Still might be a bit soft at the top, but that might be mind messing with me because in reality I'm not having to barely push the pedal for the brakes to brake.

Thanks for all your advice on this... in the end I just don't think I have the speed bleeders.

[[__--MUD--__]]

Originally Posted by pdxrealtor

I don't know if things just had to warm up or what but they're firmed up real nice. Still might be a bit soft at the top, but that might be mind messing with me because in reality I'm not having to barely push the pedal for the brakes to brake.

Thanks for all your advice on this... in the end I just don't think I have the speed bleeders.

At the top of the pedal, you are feeling the rubber lines expanding to their max. Another mod to add to your wish list, really tightens up the braking feel-

http://crownperformance.com/hummer/

FYI, there are 6 rubber lines on the H2 to replace. They give you a nice big (size, not fat chicks chick calendar w/ your order