I am an amateur mechanic. I would like to flush all old brake fluid out and install new in the 95. Is there a pattern or order of which wheel to start and finish? The fluid is rather dark and I bought the car with 81k miles last fall and is now 83k.

 

I just did mine on my 92 and I just started at right rear and worked my way forward. Not sure if that is the recommended way but it worked fine for me. I looked around on the forum and didn't see anything against doing it that way. I have a nice firm pedal and the car brakes great so I'm thinking it would work for you if there isn't any big difference between a 92 and 95.

 

*Compress all the pistons
*Suck or siphon out the reservoir
*Fill reservoir, open all bleeders, the will begin to flow fluid ("gravity bleed"). Let each run until it's clean fluid coming out, then close that one (fronts usually finish before rears)
*After closing the last one, pump the pedal to move the pistons/pads back out to the rotor, filling the caliper bores with new, fresh fluid.
*Top off fluid in reservoir.

30 minutes or less. Fast. Easy. Effective.

 

Thank you sounds easy. We’ll try that.

 

...and never let either of the reservoirs run dry during the bleed....keep fluid at least 1/3 full at all times to avoid air getting into the system...

 

Tom, i thought there was some special procedure because of ABS. Does this flush out the ABS pump as well?

 

I will let Tom answer as he knows way more than me but I have asked this question for years. I believe the answer is NO it does not flush the ABS. You need a Tech 2 to cycle the ABS to flush the fluid in it. I wish Chevy had put a switch on it to cycle and flush the fluid. My only idea is to wait for an ice storm and go to a parking lot (if you can get there) and spend an hour constantly naturally cycling the ABS. Dan

 

IMO a great tool for one person brake bleeding is the Allstar bleeder. I've used it and found it to be the best of all methods I have ever used. I believe by using the pedal pressure versus just gravity you will flush more contaminates from the system and it's much less messy. You can find it at Summit Racing.

 

IMHO - if all you're doing is flushing the system - the order you do the wheels in is fairly irrelevant. In a C4 w ABS - the fluid flows to the ABS pump and back to the individual wheels. So - there is probably more brake line between the Master Cylinder and the front calipers than between the master cylinder and the rear calipers.

Just run enough fluid through that the fluid comping from the caliper bleeders looks very similar to what you're pouring out of the container.

 

If doing the ABS is a requirement, you need the GM scan tool. I don't have one, so what *I* would do, is bleed it out as above, then go activate the ABS on some sand or something. This should mix "old" brake fluid in the ABS module w/the new in the system, then I might re-bleed.



I totally agree on both counts. The line to the front IS longer than to the rear, for sure, and I've never seen a real world situation where order mattered. I do all 4 at the same time b/c I'm impatient, don't want to wait.

 

For a long time, I used a Might Vac into a gallon pickle jar where I drilled and mounted some brass nipples into the lid and would suck it out the brake bleeder. Though I never liked it as i would suck air past the threads, and so you never really knew when/if you got all the air out of the system. Recently, I decided to just get some Russel Speed Bleeders. The FSM for my 89 I believe gives the order of RF, RR, LR, LF. So that's the order I do them in. And yes, never let the brake fluid run empty or else you'd be best pulling the master cylinder and bench bleeding it and then starting all over. My last brake fluid change, I went with Prestone MAX Dot 3, as it seems that fluid is supposed to last longer than the regular brake fluid.

 

I just facepalmed. I’ve done this twice...once to flush after purchase/brake job and again after replacing the rubber lines with braided SS. I just blindly did the RR LR RF LF pattern (no I didn’t check FSM). I didn’t think about the ABS module being behind the driver seat!

FWIW I use a vacuum bleeder at each wheel, one wheel at a time.

 

If the system has air in it - MAYBE the order matters a bit, but if you're just trying to get fresh fluid into it - I really don't see a whole lot of "issues" with starting at whatever wheel is most convenient.

I used to vacuum bleed as well, but as colter said - the problem is that you get too much air "leaking in" around the bleeder screw - so IF you are bleeding due to getting air in the system, you don't really know when the air is gone...

What I do now is this... I either buy a Motive adapter for the Master Cylinder of the car I'm going to be working on, or I get a spare master cylinder cover and drill / tap it for 1/4 NPT. I then screw a standard air compressor fitting into the cap - or connect one to the Motive Adapter. I then get a small (I use a 5 gallon) air tank and pressurize it to about 15 psi. I then run the compressed air from the tank to the master cylinder reservoir. So - the reservoir is now pressurized to about 15 psi. This is not enough pressure to cause the plastic reservoir to fail, and since it's coming from a tank that's at 15 psi - no way can a faulty regulator cause an issue. BUT ... It creates enough pressure on the master cylinder to slowly push fluid through the system, just open a bleeder screw on a wheel, and brake fluid will flow out. Typically I do one wheel, then refill the reservoir, and move onto the next wheel. Just keep an eye on the reservoir, as you go.

 

I mean....you can do that w/out pressure....and do all 4 at the same time. It's innovative and creative....I just don't "get" the need. (?)

 

What do you mean reservoirs? There is just 1 master cylinder correct?
There is no air in the lines and I’m not to worried about ABS. I just don’t trust anyone to work on the car as I haven’t found the corvette guru expert person yet.

 

Absolutely NOTHING WRONG with the old gravity bleed process!!! I still see pro mechanics using it. But it will take Quite a while to get the old fluid flushed out that way.

Using 15 psi or so - I typically go through most of a reservoir of fluid in about 2 - 4 minutes (depending on the car, the size of the reservoir, and the amount you open the bleeder screw)... which is typically enough to get clear fluid out of one caliper...