Procedure to change brake fluid?

[sothpaw]

What is the quickest way to drain out the old brake fluid, plus bleed the
system of air, for an early LT1 C4?

My Haynes manual shows the bleeding procedure but I can't find anything
that tells you what hose to pull to drain the fluid. Also, it mentions that
depending on where you introduce air, you might have to bleed one or more
wheels. I'd like to bleed just one if I could get away with it.

Also, are there any inexpensive gadgets I could get that would make this a one man job, so I wouldn't need an assistant on the pedal?

Thanks
a

 

[tlong]

If you have a jack and stands then buy a Motive Power Bleeder. $50. If you are going to the trouble why not do the brakes too? J55 bolts on to your car. New pads and stainless hoses would require bleeding and installation of fresh fluid. If the system is OK you may want to go to a Jiffy lube or brake place. It's not much to flush with new fluid and is considered routine maintenance.

The dealers have the machine to get into the ABS and really clean it all out, but bring the cash box.

I liked doing the whole job myself, rotors, pads, lines. It freaks out passengers to haul down from 70 to zero in a breathtaking decel, something unexpected in a vette.

 

[sothpaw]

Can I buy the Motive bleeder locally? Will it make it a one man job?

What hose do I drain from? Can I bleed one wheel only?

--I do have the jack stands, and I jack the car up anyway when I change tires.

--The reason for this is: I have a track day coming up, and I want fresh high temp fluid in there; my stuff is 2 years old.

 

[Vettelt193]

you can do one of a couple things to do it yourself.

One company makes a hand pump, to suck the fluid out of the system

Another way are the speed bleeder valves

the third(the way i do it)... this way isn't perfect, but pretty close to it.

I bought a bleeder bottle from a local parts store (all of the should have it for about $5). it is a bottle, hoses, and a magnet to stick the bottle to the brake.

You have to do all 4 corners, or you won't get all the fluid out of the lines... that is inevitable

Starting with the passenger rear, you loosen the bleeder screw, attach the hose/bottle. take off the cap of the brake fluid fill, fill it up, and pump the pedal. The main thing is to not let the fluid run dry!!!!

The hose is clear on the bottle kit, so you can tell when you have fresh fluid coming out.

The first wheel will take quite a bit... brake fluid is cheap, waste some fresh fluid to make sure it is nice and clean.

after the first corner is done, move on to the drivers rear, then passenger front, finishing with driver front. (you are moving from farthest to closest to the master cyl.)

As long as you keep fluid in the system, and never let it run dry, this will work just fine. it is cheap, and you can do it yourself.

 

[Vettelt193]

Can I buy the Motive bleeder locally? Will it make it a one man job?

What hose do I drain from? Can I bleed one wheel only?

--I do have the jack stands, and I jack the car up anyway when I change tires.

--The reason for this is: I have a track day coming up, and I want fresh high temp fluid in there; my stuff is 2 years old.

the motive bleeder is the hand pump, definitely a one man job then. I don't think it is necessary though. gravity will keep the lines filled when the pedal isn't being pumped, so you can get out of the car and tighten the bleeder screw by yourself.

 

[tlong]

The power bleeder was the best part of the job. It is a mini garden sprayer. You are scaring me a little when you ask about what 'hose' to pull. The system is bled at the bleeders. You pressurize the system and bleed at the calipers. You must do all four. You understand hydraulics, right?.

The speed bleeders have a valve that lets it out but no air back in. Good product for one man job, but the problem is pumping the master cylinder and introducing much farther travel than usual. Any crap in there goes down the tubes and causes big problems.

The Motive PB is in the catalogues hopefully strewn about your coffee table or at their website. Really a great product.

 

[sothpaw]

You are scaring me a little when you ask about what 'hose' to pull.

I was thinking you had to pull a hose to drain the old fluid out, replace the hose and bleed the system at the wheel(s).

So the motive pump pulls some(or all) fluid out of the master cyl, then you add and bleed? Or are you just draining the old fluid out at as you bleed the sys. at the wheels?

1 man job-- you still have to pump the pedal and look for bubbles in the plastic hose, right? How do I do those 2 things simultanously? The motive pump doesn't eliminate the need to pump the pedal and look for bubbles, does it?

 

[tlong]

The answers to all of your questions are on their website. The process is to fill the Power Bleeder with your favorite flavor fluid, ATE is blue so you can't miss it, but new clear amber is quite apparent also. You attach the bottle to the master cylinder with supplied cap and pump it up to 20 lbs. There's a gauge on the tank....You have to move the ECM out of the way. Simple.

You bleed each caliper by putting a supplied clear plastic aquarium hose on the tip of the bleeder screws into a coffee can. When the hose turns blue and no bubbles, tighten the bleeder screw. It forces the black nasty old stuff through replacing it with the desired fresh juice. How did I do?

 

[Vettelt193]

I was thinking you had to pull a hose to drain the old fluid out, replace the hose and bleed the system at the wheel(s).

So the motive pump pulls some(or all) fluid out of the master cyl, then you add and bleed? Or are you just draining the old fluid out at as you bleed the sys. at the wheels?

1 man job-- you still have to pump the pedal and look for bubbles in the plastic hose, right? How do I do those 2 things simultanously? The motive pump doesn't eliminate the need to pump the pedal and look for bubbles, does it?

Most of the fluid is in the lines and master cyl. The most effective way of doing a change is to force fresh fluid through the system. With brakes you usually don't do a drain/fill type procedure.

 

[sothpaw]

Most of the fluid is in the lines and master cyl. The most effective way of doing a change is to force fresh fluid through the system. With brakes you usually don't do a drain/fill type procedure.

LT193,

So when you do the flush, (you don't use the pump), you just start at the right rear, bleed some, add new fluid, and the old stuff comes out thru the valve at the wheel by gravity feed?


Glad to see you have your LT4 back. Is it the same one?

--Thanks to both of you, I think I've got it now.

 

[Vettelt193]

same car, bought it back And now I am considering selling again... I am buying a condo as a second home and would feel better if I had a lower insurance bill and some extra money in hand.

back to the subject:

it won't gravity feed fast enough... it will take forever if you did it like that... what i was trying to say is, gravity will keep the fluid trickling down the line, so you really don't have to worry about air back-feeding into the caliper (this is why people get a helper... so as soon as they are done pumping the second person can tighten the bleeder screw) in my experience, it isn't necessary.

To do it like this, the first brake will take the most time, as all the old fluid in the overflow, and in the master cyl. will need to go through the lines and out the brake. Once it is running clear, which will take multiple dumps of the old fluid in the little container, and multiple refills; the other brakes will be much quicker, as the only fluid you are getting out is the stuff in the lines.

It is probably a 2 hour job, taking your time and having a couple beers... it is not difficult by any means, and braking power is much better. I bought an old honda a few years back, as a daily driver, and the brakes stunk... after i did the fluid, it was like a whole new car. After doing some research on fluid, i found that in the southern states (Florida for sure) where humidity is high, the fluid is about 50% less effective after only 1 year. after 2 years, it can be dangerously unsafe at high temperatures.

 

[GeorgeT]

According to the Helms manual, you start by bleeding the old fluid from the ABS unit located under the hatch area behind the Driver's seat, then the rr, lr, rf and lf respectively.

 

[WhalePirot]

Using a hand pump (finally found a metal one) to suck the fluid through each item, in order, as described, is a one man job. Just keep checking the reservoir, as has been emphasized, to not go 'air'. Put the wrenchon the bleeder, slip the hose over same, 'crack' open the bleeder, and pump. When the fluid goes clear, tighten the bleeder, install the rubber cap and go to the next bleed site.

I change my fluid when it gets dark, in all cars.