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ABS pump questions - cleaning

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    ABS pump questions - cleaning

    I am replacing the axle on my 1990 325ix and I have replaced all the rubber brake hoses. When cutting old brake lines , it had very little fluid in them.

    Have the axle installed and was going to bleed the brakes and cannot get any fluid to the back. This vehicle has an ABS system. Read several threads - pumped the brakes 12 times etc. Used a hand vacuum pump - nothing.

    Front brakes work.

    Inspected lines to the pump - getting fluid to the rear brake line feed at the pump. Opened the rear line from the pump (labeled h on the pump) nothing coming out. Assuming blockage in the pump?

    Is it possible to clean the screens in the pump without a complete disassembly? - I dont see a good write up - just people concerned about removal of parts that are staked in.. (see below)

    My unit is BOSCH 0 265 200 040 - will other E30 pumps work? or must I get the exact match? Or must it just match the ABS ECU?

    Rebuilds are too expensive at this point

    thread on cleaning -

    You need an air powered vacuum bleeder.


      Just for background - the car has been sitting in my backyard since around 2018. It was in a black ice accident and parked - i have ran it each summer and cleaned washed enough to keep it servicable but other than that - it has encountered a bit of rot and I am working on getting it on the road.

      When I cracked open the rear brakes there was no fluid (very little) so most likely it had not had any fluid in the rear lines for many years,

      I believe the pump could be gunked up with old fluid.


        symptoms do match with a bad pump.

        i know they can be cleaned up but i think you may need special tools. it's usually more than a clogged screen. stuck from this forum and others sells refurb units but they are not cheap by any measure even rebuilt. some guys consider doing the delete just as a cost saving measure. if/when mine goes i will probably simply delete it. i'm not a huge fan of early abs systems from that era.

        edit : LATE040 - BOSCH: 0 265 200 040 (BMW PN: 34 51 1 157 011) – MTechnique ABS


          There is no way to clean the screens without complete disassembly, and the screens aren't what generally causes a complete blockage in the first place. There are also a number of parts that simply need to be replaced, and they aren't available.... I manufacture them new.

          If you have a 040 unit you'll need to stay with it, but even then there are multiple variations of it, mainly cosmetic in nature. You most likely have a "MID 040" in 1990. I have several dozen cores on hand and can build one to ship out in a few days if you want a fully refurbished and tested unit, then you can return yours as a core.

          You can also pull yours and send it ahead if you prefer your original unit refurbished, either way is a good choice.

          You're welcome to contact me here, or through my website.
          Tenured Automotive Service Professional - Avid BMW Enthusiast

          Vapor Honing & E30 ABS Pump Refurbishment Service


            i'm not a huge fan of early abs systems from that era.
            I also have my reservations, having run afoul of it several times ages ago.

            I don't know if it's still available, but at one point there was a 'standalone' MK60 ABS system available
            that was reputed to be easy to fit to an E30. But that's internet hearsay from years back.
            I have a project car that has the ABS pump still in it, and if I was to resurrect that with ABS, I'd try to use MK60.
            Because it's pretty good, as I've found in multiple situations.

            now, sometimes I just mess with people. It's more entertaining that way. george graves


              I did try a pneumatic vacuum pump - FAIL :)

              I appreciate the insight on a rebuilt - Ill keep your company in mind Jordan.


                Just a quick UPDATE

                Picked up a used pump - same number - same year vehicle (ECU came with it) 110K miles - ($35) Wanted a spare in case - so I bought it.

                Read through some other threads and decided to a few more checks before removing. Jim Levie (RIP) mentioned the symptoms of no rear (or no front) would most likely point to a master cylinder problem.

                I would get some fluid from the Master cylinder to the pump - but not in a steady stream - could not pull a fluid stream from the Master cylinder - only intermittent fluid when pushing the pedal.

                So now I am looking at a Master Cylinder issue - I want to make sure that is the case before switching anything out.


                  I can tell you it is rather uncommon that both front circuits become obstructed, ( left front only is rather common ) but rear obstruction is the most common. That said just because a pump passes fluid through on all three circuits does not mean that the maintain or reduce functions set and seal properly either.

                  Send me your original pump and I'll test it on my hydroelectric rig for free and tell you what is wrong with it. If you want it completely refurbished awesome, if you don't no worries just cover the return shipping.
                  Tenured Automotive Service Professional - Avid BMW Enthusiast

                  Vapor Honing & E30 ABS Pump Refurbishment Service