kherr
Premium Member
join:2000-09-04
Collinsville, IL

[Brakes] Bleeding Brakes ….. Newbee

1994 S10
Front ABS

OK so I replaced Master Cylinder.
Bled it in-place with lines disconnected ….adapters in their place w/tubes feeding back to reservoir, pumping pedal slowly till bubbles gone.
Replaced both rear brake lines. I made sure MC didn’t drain below levels. By the time I connected to brakes, fluid was coming out of the line.
Used a bleeder that hooks up to a compressor.
Disconnected power from ABS box when bleeding front.
Between the four I drew out about 1-1/2 pints of fluid
When depressing pedal, they’re hard. Engine off.
With engine on, pedal goes to floor …. Brake light on …. ABS light on.

So what did I do wrong. This is a first time effort, so please be kind ….

TIA

Kevin


shdesigns
Powered By Infinite Improbabilty Drive
Premium Member
join:2000-12-01
Stone Mountain, GA

[Brakes] Re: Bleeding Brakes ….. Newbee

The ABS will probably have bleeders. Try bleeding there.
Had a Surburben that did the same, turned out to be cracked caliper.

kherr
Premium Member
join:2000-09-04
Collinsville, IL

…bled them at the wheels … nice flow … would there be another place also ???
it’s been sitting for 4~5 years, and was fine the last time I drove it. If there was a leak in the front lines .. would the pedal be hard when the engine is off.


shdesigns
Powered By Infinite Improbabilty Drive
Premium Member
join:2000-12-01
Stone Mountain, GA said bykherr:

would there be another place also

Like I said, bleed the ABS unit.
cowboyro
Premium Member
join:2000-10-11
Shelton, CT 341.6 41.4 to kherr

Re: [Brakes] Bleeding Brakes ….. Newbee

Do it the old fashioned way with a helper… pump pump, open bleeder, push, close bleeder… pump pump… add fluid to the reservoir as needed and continue until you get clean fluid out.
Not only you get rid of bubbles faster, you also get to flush the circuit, double win.


Thane_Bitter
Inquire within
Premium Member
join:2005-01-20 ·Start.ca to kherr

Re: [Brakes] Re: Bleeding Brakes ….. Newbee

If the leak was small the system could still build up pressure and thus the pedal would get hard, however if you kept constant pressure on the pedal you should notice that it would slowly sink to the floor. You can check for this with a tape measure.

I’m cheap so I use the tube and bottle system for bleeding, also brake fluid is relatively cheap, I normally use the OEM stuff, but for bleeding purging I get the cheap stuff and use it to blow out the system and then refill and purge with OEM fluid. Having someone pound away on the brakes before you crack the bleeder valve can help dislodge air bubbles. The rapid change in pressure causes the bubbles to shrink or expand which helps break them free. Again with the tube you can watch air or other matter coming out of the bleeder screw.

But why is the brake light on, on most cars the light is wired to the parking brake and to a float switch in the MC which trips if the fluid is low?

Trimox
join:2012-09-24
Anywhere

to kherr

Since I had to work on vehicles by my self quite often (and I’m cheap and lazy). I would run tubing on all four bleeder screws into cans at each wheel and open them. Then just keep master cylinder from running out. This will bleed and flush master cylinder and all. It might take a while but it has never failed me.

kherr
Premium Member
join:2000-09-04
Collinsville, IL

Re: [Brakes] Bleeding Brakes ….. Newbee

Dad came over to help me bleed them …. turns out front left had a broken fitting. Now to find someone to flare the line for the fitting that goes on the ABS box ….

lawsoncl
join:2008-10-28
Spirit Lake, ID

to Thane_Bitter

Re: [Brakes] Re: Bleeding Brakes ….. Newbee

said byThane_Bitter:

on most cars the light is wired to the parking brake and to a float switch in the MC which trips if the fluid is low

The MC switch is sometimes a limit switch inside the prop valve that’s tripped if either the front or back isn’t developing pressure.

radios1
join:2017-11-10

to kherr

Re: [Brakes] Bleeding Brakes ….. Newbee

said bykherr:

Dad came over to help me bleed them …. turns out front left had a broken fitting. Now to find someone to flare the line for the fitting that goes on the ABS box ….

I think you are better off replacing the line, since it’s a brake line, and it needs a double flare. and it may have been rusted. how long is it?..

kherr
Premium Member
join:2000-09-04
Collinsville, IL

I’m replacing the line. I need the fitting that goes to the box put on. I can get the tools, but don’t want to try on my own …

LittleBill
join:2013-05-24

buy some brake line and practice, its not that hard. i never used one and had it down in under 10 attempts

radios1
join:2017-11-10

to kherr
said bykherr:

I’m replacing the line. I need the fitting that goes to the box put on. I can get the tools, but don’t want to try on my own …

usually, when you go to an auto parts store, they have the brake lines pre bent, with the fittings attached, unless you want to make something custom..

kherr
Premium Member
join:2000-09-04
Collinsville, IL

finding the exact one i need would be pretty slim at best … even on the web for a 24 year old truck.

i’m buying straight ones with the normal fittings on them. the fitting i need isn’t available on them … to say nothing of the length …

radios1
join:2017-11-10

said bykherr:

finding the exact one i need would be pretty slim at best … even on the web for a 24 year old truck.

i’m buying straight ones with the normal fittings on them. the fitting i need isn’t available on them … to say nothing of the length …

they have them here. »www.autozone.com/brakes- ··· ake-lineis it this one? »www.autozone.com/brakes- ··· 74_90075

LittleBill
join:2013-05-24

said byradios1:said bykherr:

finding the exact one i need would be pretty slim at best … even on the web for a 24 year old truck.

i’m buying straight ones with the normal fittings on them. the fitting i need isn’t available on them … to say nothing of the length …

they have them here. »www.autozone.com/brakes- ··· ake-lineis it this one? »www.autozone.com/brakes- ··· 74_90075the issue is usually the fittings, some of them use weird fittings i had to replace the entire brake system on a ford, some fittings had to be reused since no one sold just the fittings

radios1
join:2017-11-10

said byLittleBill:said byradios1:said bykherr:

finding the exact one i need would be pretty slim at best … even on the web for a 24 year old truck.

i’m buying straight ones with the normal fittings on them. the fitting i need isn’t available on them … to say nothing of the length …

they have them here. »www.autozone.com/brakes- ··· ake-lineis it this one? »www.autozone.com/brakes- ··· 74_90075the issue is usually the fittings, some of them use weird fittings i had to replace the entire brake system on a ford, some fittings had to be reused since no one sold just the fittingsthese are supposed to be designed for that particular vehicle, and would have the correct length and fittings, just like any other part made for the vehicle..

kherr
Premium Member
join:2000-09-04
Collinsville, IL

those look VERY INTERESTING …….. thanks for the link. i’ll take my fitting up there and see what they can do ……


Sr Tech
Premium Member
join:2003-01-19
Meriden, CT to kherr

When I used to change a master cylinder, after installing it I would fill the res, pump the break pedal and hold, have another person crack each of the lines open at the cylinder and bleed out any air from there first before going to the wheels. Or put the master in a vice, fill it and push the back with a rod in order to bleed out any air before installing it. You must have air trapped, not sure what others posted but you may want something to draw the fluid at the wheel to pull the air out.

kherr
Premium Member
join:2000-09-04
Collinsville, IL

good tip on bleeding the box …. there’s bleeder valves on top of it. AFA the MC .. i bled it in place … removing the lines … putting on fittings/tubes going back to the reservoir …. slowly pumping till no more bubbles. …


rainblood12
Would You Like Fries With That?
join:2002-11-16
Union, NJ to kherr
I had a similar situation on my 96 saturn when I had to replace the MC and ABS unit. The ABS pistons needs to be reset to their home position before you can bleed the system (correct me if I’m wrong). What I did to do this was spin the front wheels in mud until the ABS kicked on, which reset the pistons. Or else you need a GM tool to do it.

Usually I bleed in sequence. Front Right, Rear Left, Front Left, Rear Right.

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