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View Full Version : Can anyone recommend a brake bleeding kit and any tips on the job!



leicesterboy15
09-17-2010, 05:28 AM
I've never done this before so I've decided to undertake this job while also replacing the discs and pads. I have an assistant for the job as we will be doing 3 cars but there is a huge array of brake bleeding kits out there and was wondering if anyone had any experience with them and could recommend one?

Also, are there any tips or gotcha's in there that I need to be aware of?

BTW I've not been here for a while because of holidays and work but the new look is great!

Bo525i
09-17-2010, 06:02 AM
I´m guessing that you have the ASC+T like I do, so I´m listening in on this one! :)

leicesterboy15
09-17-2010, 10:51 AM
err....yes I do, I didn't think that made a difference until you posted, now I'm thinking it does!

Mr._Graybeard
09-17-2010, 11:06 AM
Pressure bleeding is the way to go, IMO, althought the simplest, most foolproof (but slowest) option is to simply open a bleeder and let gravity do the work. Just keep the reservoir filled with fresh brake fluid and it works fine.

The most basic pressure bleeder is an old reservoir cap with a Schraeder tire valve mounted in it, along with an air compressor or other similar source equipped with a tire chuck. Some people use the air in the spare tire -- that's the approach behind the Eezibleed kit. http://www.autoexpertproducts.com/eezibleed.htm

Generally the air pressure should be kept fairly low, like 10-15 PSI, which is why a regulated pressure source like an air compressor is ideal. Another option is the Motive bleeder, which is basically a modified Hudson-type pressure bottle with a pump. http://www.motiveproducts.com/

Motive recommends putting fresh fluid into the pressure bottle and forcing it into the reservoir; I've never done it that way. I suppose there might be a slight benefit to that (compressed air tends to carry moisture) but it always seemed like a messy way to go with a product that can damage paint so readily. I'd rather apply pressure at the reservoir til the fluid level drops, release pressure and refill the reservoir.

A couple things about the Motive unit: It's pricey for what it is. I got one years ago for $40 -- now they're $50 and up. If you can get hold of an old Hudson sprayer, a hose barb fitting and an ATE brake reservoir cap, you have the makings of a Motive clone for a lot less than $50. Another issue is the way the Motive hose is attached to its reservoir cap ... it's simply clamped on, which means there's no swivel to facilitate screwing on the cap. It's a poor design. That's why I prefer the tire valve/tire chuck approach.

I tossed my Motive bleeder when the seals failed in the pump. There was also a pressure gauge in the unit, which also stopped working after awhile. Overall, it was a disappointment.

As for the actual bleeding process, start with the rear wheel farthest from the master cylinder, then do the other rear wheel, then the front wheels the same way. You'll use about a liter of fluid -- about three-fifths of it for the rear wheels, two-fifths for the fronts.

A note with traction control and ABS: Take care to keep the reservoir well filled as you bleed! If you get air into the system, you may have to take the car to the dealer to get it purged.

Robin-535im
09-17-2010, 05:39 PM
Yeah - what he said! Plus... Bill R. posted the official BMW procedure once upon a time, probably in the maintenance forum. IIRC they recommend using a combination of pumping plus the pressure bleeder. 12 pump/release cycles while the pressure bleeder was ALSO pressurizing the lines. I've had the "luck" of being an unlucky bleeder, it usually takes me twice around to get the pedal feel back. Using the different colors (ATE Blue / Gold) is helpful as it's sometimes hard to see when it's clean. On e39's at least, maybe also on e34's, the dealer has a way to actuate the antilock brake system to make it squirt out the old fluid that hangs out in the ABS unit.

whiskychaser
09-17-2010, 06:28 PM
I've had an Eezibleed kit for years. IIRC it was made by Gunsens of Colourtune fame. I bought it so I could bleed brakes single handed. You just fill the container with brake fluid. Attach one tube to a tyre at 12 psi and the other to the reservoir cap. The kit came with different caps and seals. They seemed to fit fine but still leaked. Despite that it worked fine. Seem to recall reading that if you dont use a pressure bleed system you can get an air lock in the abs pump and its an absolute pig to shift. Somebody chime in and confirm I am right or my memory is playing tricks again

Tiger
09-17-2010, 09:15 PM
Bavarian Autosport got the best pressure bleeder. I got the original version. It looks tricky at first, but it is not... It is best to suck out old fluids first and fill back to normal level. Then hook up the pressure bleeder and pump up to like 25PSI. Don't worry about air in the line from the reservoir to the cap... as long there is fluid in the cap zone... it will automatically replenish it to the same level... Make sure the tank is level or at least leaning toward the line side... so fluid goes in.

When you are ready to stop... flip the tank on the side so it doesn't replenish the brake fluid to the line... and keep draining from the caliper until the reservoir is at the proper level... Then tighten up the bleeder valve... and then gradually release the pressure from the tank by unscrewing cap slowly or if your tank has the pressure relief valve.

leicesterboy15
09-20-2010, 08:49 AM
Ok thanks guys, I am going to invest in the eezbleed kit and tackle this weekend assuming there is no rain and time permitting - I replaced the valve cover gaskets the other week and one is leaking so I need to re-seat it first, at least that way 1 job will be done properly rather than starting the brakes and ending up with two incomplete jobs :)

sal_park
09-21-2010, 06:45 AM
Hi LB15,

I've also used an easybleed kit with my 525 which worked very well. While I agree with what is posted above, I would add the following:

I suggest using the spare wheel because you really want to reduce the pressure you feed into the EB kit to around 12 psi as stated above. Really important !

After you've tighten up the cap on top of the reservoir expect to get a leak. I had to tighen mine up to the point where it was going to seal or break :)

After you get a good seal and the EB kit is maintaining pressure you'll need to release the pressure at some point. Do this very very very very VERY slowly, otherwise you end up with brake fluid everywhere. Go on, ask me how I know :)

hth

sal

shogun
09-21-2010, 08:07 AM
family bleeding
http://www.pelicanparts.com/bmw/techarticles/Mult-Bleeding_Brakes/Mult-Bleeding_Brakes.htm

Tiger
09-21-2010, 09:28 AM
I don't recommend faminly bleeding at all. The reason is that typical movement in the master cylinder wears the cylinder in a certain way... Once you do family bleeding... you push the seals beyond that wear point and then damage the seal. The result is master cylinder failure... you can't stop the car unless you rapidly pump the pedals... and you can't stop it hard enough... that you can get into accident.

Fortunately it didn't happoent to me while I am driving, but it has to other people. My friend who is a mechanic see it all the time after that type of bleeding... it is all good for them right? More business.

Tiger
09-21-2010, 09:30 AM
True... but first lesson right? LOL.

Kibokojoe
09-27-2010, 09:44 AM
I bleed my brakes with a small jar filled with brake fluid. I soldered a 1/8" copper tube to the jar lid and the tube extends down into the brake fluid. Then using a clear flexible hose connect the copper tube to the brake zerk. Open the zerk and slowly pump the brakes, making sure the brake resevior stays full. As long as the copper tube in the jar is flooded it can't draw air back into the system.
http://i273.photobucket.com/albums/jj225/kibokojoe/brakefluid.jpg

ss2115
09-27-2010, 04:45 PM
Tiger is 100% correct!
You shouldn't bleed brakes by pumping the pedal.
Brake fluid is hydroscopic - absorbs water which collects at the bottom. All the time in the master cylinder there is a small amount of water constantly sitting just beyond the normal area the cup seal travels up to. This small amount of water rusts tiny pits, but because the seal doesn't travel over it normally, its not a problem.
However, when you bleed the brakes by pumping, you are pushing the seal the full length of the barrel and the edge of the seal runs over these pits and damages its edge.
This means that when the brakes are being applied, there is a small amount of brake fluid escaping past the seal around the damaged area and this rapidly becomes worse over time until you have a brake failure.
If your lucky, you'll notice the brake pedal is getting lower before the car is pulling up, and/or if your sitting at lights with your foot on the brake and it seems to be ever so slowly sinking away, then you'll realise its time for the master cylinder to be overhauled or replaced.

leicesterboy15
09-28-2010, 08:49 AM
Well we gave the eezibleed a go and it does work well but there are 3 tips you MUST follow:

1. Ensure your chosen cap is screwed tightly into the hose.
2. You MUST make sure the rubber washer is flat in the cap.
3. DO NOT over tighten the cap to the reservoir, it says in the instructions to tighten until you feel resistance then no more than a 1/4 turn more - this is true :) I tend to over tighten things but it definately makes it worse in this case.

If you don't do these then when you apply the pressure the kit will leak!

Other than that it works really well, keep the PSI low (12 as previously suggested), you can always increase it later and make sure you are organised and the job will stay clean othrwise it can get messy. The caliper bleeder bolts are 7mm and you may need to spray them with WD40 to ensure you don't round them off.

We used the family member procedure on the other car and it worked without too much fuss but it was a bit messier and you were never convinced the fluid was bleeding all the way through the system.

Another tip: If you can use a different colour brake fluid, this will help a lot with knowing when the old fluid is out!

leicesterboy15
09-28-2010, 08:52 AM
Tiger is 100% correct!
You shouldn't bleed brakes by pumping the pedal.
Brake fluid is hydroscopic - absorbs water which collects at the bottom. All the time in the master cylinder there is a small amount of water constantly sitting just beyond the normal area the cup seal travels up to. This small amount of water rusts tiny pits, but because the seal doesn't travel over it normally, its not a problem.
However, when you bleed the brakes by pumping, you are pushing the seal the full length of the barrel and the edge of the seal runs over these pits and damages its edge.
This means that when the brakes are being applied, there is a small amount of brake fluid escaping past the seal around the damaged area and this rapidly becomes worse over time until you have a brake failure.
If your lucky, you'll notice the brake pedal is getting lower before the car is pulling up, and/or if your sitting at lights with your foot on the brake and it seems to be ever so slowly sinking away, then you'll realise its time for the master cylinder to be overhauled or replaced.

Ooops.....well the e34 will be OK but the corrolla is screwed!