Brake Pressure Failing!

[drmccaa]

Hello fellow E30 owners,

I've run into a bit of a situation with my E30, and I'm hoping to tap into the collective wisdom of rv3limited. So, here's the deal: I recently took my beloved 1985 318i for a routine checkup at the local garage. Everything seemed fine until the mechanic dropped the bombshell that my brake lines desperately need a flush. Now, I'm not exactly a DIY expert, so I thought I'd turn to you all for some guidance. Have any of you experienced similar issues with your E30s? Is a brake line flush really necessary, or is this just another way for the auto shops to rip us off? If a flush is genuinely needed, any recommendations on how to do it at home, cost efficiently?

[reelizmpro]

The brake fluid in the reservoir is probably dirty so they want to do a "flush" and fill. Most people will just flush the line with fresh fluid (brake fluid change) and call it a day. Apparently, there is a chemical flush but I wouldn't say it's a thing since you really don't want anything but brake fluid in your brake system. If you're asking how to do it, you should just let a shop do it for you since the brake system is a critical system that has to work properly. Any competent full service or brake shop will be able to do it.

[digger]

yes, you should flush and bleed the brakes periodically or have it done by a shop.

Get yourself a motive pressure bleeder (or similar) with the BMW reservoir adaptor, a bunch of dot4 fluid and DIY. or the cheapest way is to get a friend who works for free to work the pedal and you bleed with a bottle and hose starting from further caliper from M/C and working to the closest. Its pretty straightforward only gets complicated sometimes if you are changing the M/C

[ehrawn]

Hello fellow E30 owners,

I've run into a bit of a situation with my E30, and I'm hoping to tap into the collective wisdom of rv3limited. So, here's the deal: I recently took my beloved 1985 318i for a routine checkup at the local garage. Everything seemed fine until the mechanic dropped the bombshell that my brake lines desperately need a flush. Now, I'm not exactly a DIY expert, so I thought I'd turn to you all for some guidance. Have any of you experienced similar issues with your E30s? Is a brake line flush really necessary, or is this just another way for the auto shops to rip us off? If a flush is genuinely needed, any recommendations on how to do it at home, cost efficiently?

Brake fluid will absorb water over time and lead to failures. The standard E30 cycle is a flush every two years. A decent service shop will test for water content if you don't know how long it's been. My shop charges $155 to do the job, for reference.

[monty23psk]

Flush should be done every 2 years regardless of mileage. Simple job as stated above, buy the Motive pressure bleeder and brake fluid. Start at rear passenger side, then rear driver, then front pass, then driver side to clean out the dirtiest fluid first. Highly recommend this to catch the fluid. You can even use this with out pressure bleeder if you really have too. Just make sure check valve is working correctly.

[Panici]

Flush should be done every 2 years regardless of mileage. Simple job as stated above, buy the Motive pressure bleeder and brake fluid. Start at rear passenger side, then rear driver, then front pass, then driver side to clean out the dirtiest fluid first. Highly recommend this to catch the fluid. You can even use this with out pressure bleeder if you really have too. Just make sure check valve is working correctly.

You could alternatively use a vacuum bleeder as well at the caliper side.

I have both and find myself reaching for the Motive pressure bleeder more often for a full brake bleed job.


It doesn't really need to be done every two years on the money. Brake fluid is hydroscopic and will absorb water from the air, so will depend on how you store and drive the car.

I usually wait to see fluid discoloration in the reservoir before I worry about it, with the exception being anything that sees track time.
Fluid with water in it will boil at a lower temperature, and when your fluid boils you lose the brakes (pedal goes to the floor, or lever to the bars on a motorcycle). Sometimes you notice the increased travel before you completely lose the brakes, sometimes not.

[ehrawn]

buy the Motive pressure bleeder

Which model did you get? I’ve been looking to get one because gravity bleeding isn’t cutting it.

[digger]

Which model did you get? I’ve been looking to get one because gravity bleeding isn’t cutting it.

https://www.motiveproducts.com/products/0100-european-bleeder

https://www.bimmerworld.com/Tools/BMW-Brake-Tools/Motive-Brake-Pressure-Bleeder-BMW.html#:~:text=The%20Motive%20European%20Brake%2 0Pressure,ve%20seen%20on%20the%20market.

[reelizmpro]

That Motive pressure bleeder is the way to go because it keeps the reservoir filled automatically. I haven't had much luck with the vacuum method. It takes forever to bleed all 4 properly. On top of that you have to stop and make sure the reservoir stays filled.

[monty23psk]

Vacuum method works great and like stated, con is adding more fluid but very easy to clean up and not waste fluid which matters when using expensive versions. Here is a tool I ran into to test the fluid and will be getting one. No idea how accurate they are but BF sale going on.

https://www.amazon.com/ITEQ-Liquid-Tester-Indicators-Calibrated/dp/B076SC377J/ref=sr_1_3?crid=1JPICBQ7EPC1X&keywords=brake+fluid+tester&qid=1700703927&sprefix=brake+flui%2Caps%2C112&sr=8-3

[e30davie]

I bought a cheap hand held vacuum bleeder and the issue I found immediately is that when you crack the bleeder it sucks in air through the threads on the bleeder screw. waste of time. So all I saw in the clear tube is bubbles. So I just got the wife in the car to do it the old manual way.

Next time I do it (12 months or so) I'm buying a pressure one.

[digger]

I bought a cheap hand held vacuum bleeder and the issue I found immediately is that when you crack the bleeder it sucks in air through the threads on the bleeder screw. waste of time. So all I saw in the clear tube is bubbles. So I just got the wife in the car to do it the old manual way.

Next time I do it (12 months or so) I'm buying a pressure one.

Yep leaky threads massive pita

[monty23psk]

I bought a cheap hand held vacuum bleeder and the issue I found immediately is that when you crack the bleeder it sucks in air through the threads on the bleeder screw. waste of time. So all I saw in the clear tube is bubbles. So I just got the wife in the car to do it the old manual way.

Next time I do it (12 months or so) I'm buying a pressure one.

you need to make sure the check valve is working before. They go bad very easily due to the fluid. I bought replacement check valve 3-packs to have them handy.

[e30davie]

Check valve wont stop leaking threads on the bleeder screw...