[StuWag]

Hi Guys n Gals,

Looking for technical docs or photos /video showing a EHCS rebuild. Been wrestling with the Hydraulics all day.

Rod is not moving at all, even with assistance it doesn't take over and drive the piston at all.

Basically motor is running, gear wheel is OK, new shaft and seals on cylinder, filled and bled the unit a few times today. I started out using fork oil, changed to transmission fluid later in the day as it was heavier.
I haven't broken open the pump yet as I wanted to know what I was letting myself in for.

Ive searched the technical docs and found John Zeiler's seals list, very useful
and I've also found many people thanking Ari for his rebuild pics but the link doesn't work.

Any one point me in the right direction, and or any ideas regards the total lack of movement?

Thanks in advance!

 

[jzeiler]

Did you open the cover on the motor to inspect the brushes? If you opened the motor and put the cover back on 180 out it will run the pump backwards and there will be no movement of the shaft. Did you install the sleeve cylinder correctly with the small hole facing the main body? Lots of ways to mess this up.

No need to mess with the pump it is bullet proof and very easy to screw up the seals.

I use jack oil and do all my draining and filling on the big 19 mm spigot. I never open up the little 4 mm ports. Max fill from bone dry is 140 ml of oil.

Kirk from the Illinois BMW Club has posted a video of his version of the rebuild. I'll see if I can find it and put a link here for you. Look HERE for Kirk's video.

Also a BIG NOTE if you are bench running the unit it MUST be horizontal with the 4 mm ports facing UP or it will run and not move.

 

[StuWag]

Did you open the cover on the motor to inspect the brushes? If you opened the motor and put the cover back on 180 out it will run the pump backwards and there will be no movement of the shaft. Did you install the sleeve cylinder correctly with the small hole facing the main body? Lots of ways to mess this up.

No need to mess with the pump it is bullet proof and very easy to screw up the seals.

I use jack oil and do all my draining and filling on the big 19 mm spigot. I never open up the little 4 mm ports. Max fill from bone dry is 140 ml of oil.

Kirk from the Illinois BMW Club has posted a video of his version of the rebuild. I'll see if I can find it and put a link here for you. Look HERE for Kirk's video.

Also a BIG NOTE if you are bench running the unit it MUST be horizontal with the 4 mm ports facing UP or it will run and not move.

Thanks for the quick reply,

That's really interesting about the small hole, I thought that was a blank because there is a hole on the inside of the cylinder. Im assuming that's for oil transfer to the back of the piston. Ill Take a real close look at Kirks video again and see if I can see correct fitting.

Kirk uses the 4mm bleeds and that's how I have been doing it. I read your 19mm bolt method last night and will try that tonight after work.

Another stupid question, why would the unit not want to be full? I have added about 150ml and got as much of the air out as possible, also when I bench cycle the unit the piston will not go all the way in. you mention a relief valve, It sounds like ive over filled the unit, and I wondered if that may be an issue.

I haven't touched the motor, however it is a replacement, buts its been in since 2010 and has never caused an issue.

Ill take some pics tonight.

Thanks

 

[StuWag]

Did you open the cover on the motor to inspect the brushes? If you opened the motor and put the cover back on 180 out it will run the pump backwards and there will be no movement of the shaft. Did you install the sleeve cylinder correctly with the small hole facing the main body? Lots of ways to mess this up.

No need to mess with the pump it is bullet proof and very easy to screw up the seals.

I use jack oil and do all my draining and filling on the big 19 mm spigot. I never open up the little 4 mm ports. Max fill from bone dry is 140 ml of oil.

Kirk from the Illinois BMW Club has posted a video of his version of the rebuild. I'll see if I can find it and put a link here for you. Look HERE for Kirk's video.

Also a BIG NOTE if you are bench running the unit it MUST be horizontal with the 4 mm ports facing UP or it will run and not move.

Just watched Kirks Reassembly segment and I recon mine is correct with the internal transfer hole away from the main body.

Two more questions.

1. What is the direction of rotation of the motor?

2. I didn't have a squeezy bottle to fill the oil with, and Im wondering if my pump is still dry? I just dribbled the oil into the sprung fill port. it took ages but I thought all the air was out

 

[jzeiler]

The motor is CCW. If the internal hole was at the top of the cylinder, then you have in correctly. This shows the cover on the motor that is correct. If you installed 150 ml without losing any it is full and no bleeding is required. Just run it several times in the correct orientation.

If you want to make sure just remove the 19 mm spigot, point it down into a drain pan and push the rod in against a bench several times until no more oil runs out. Then turn it so the hole is up and start filling it as you compress the rod, it will suck the oil in. Then at the end of travel place your thumb over the hole and let the rod extend. Repeat until you have pot 140 ml in. You know you will be close as the sucking will be reduced and you will see flow in the hole from a side port. Reinstall the 19 mm spigot and set the unit horizontal as you see in the picture. It should run just fine.

 

[StuWag]

The motor is CCW. If the internal hole was at the top of the cylinder, then you have in correctly. This shows the cover on the motor that is correct. If you installed 150 ml without losing any it is full and no bleeding is required. Just run it several times in the correct orientation.

If you want to make sure just remove the 19 mm spigot, point it down into a drain pan and push the rod in against a bench several times until no more oil runs out. Then turn it so the hole is up and start filling it as you compress the rod, it will suck the oil in. Then at the end of travel place your thumb over the hole and let the rod extend. Repeat until you have pot 140 ml in. You know you will be close as the sucking will be reduced and you will see flow in the hole from a side port. Reinstall the 19 mm spigot and set the unit horizontal as you see in the picture. It should run just fine.

View attachment 181794

Hey John Thanks. Ive Just Filled the EHCS as per your instructions to Scimitar last month. Worked a lot better than using the little bleeders on the top. I got exactly 140ml of Jack oil in to the Cylinder and as you say it became a slower process the nearer I got to full.

All that said I tested the unit on the bike, setting it level on a block and plugging it in. Ran the motor and Nothing, Nada, Disappointing!! Now you say counter clockwise for the motor, I have had the motor out tonight and the Motor is really clean inside, hardly any wear to the brushes or the commutator, bearings look good, If I'm looking at the sprocket/cog from the front of the bike (as it would be mounted) it is CCW. If Im looking from the stand end of the motor then its running Clockwise, Ill Check those markers that you have highlighted in the pic.

Im sure you have better things to do than babysit me through a stand repair but I really appreciate all the help that You, Wazza and Scimitar have given over the last few days. Feel like I'm Halfway there!

 

[StuWag]

I've Just had a play with reversing the polarity on the bench using a 12V power supply which I'd forgotten I had.
Less than poor results with the polarity reversed.
With the polarity as it should be I experimented by pushing on the shaft on the edge of the bench and it went in more easily than when not running. Also the shaft was really slow to return on the springs when the motor was running. which would kind of indicate that the pump is producing some pressure, but very little.
I think I'm gonna need to break into the hydraulic pump to make any progress with this. I know precisely nothing about hydraulic pumps and what makes them tick and what it will take to get it working.
I'm guessing that your seal guide will help John, Think Ill break into it tonight and have a look.

Anyone Know of any written info on that subject, anything will help at this stage

Just started snowing here, Happy days!

 

[StuWag]

As an aside, the Hydraulic fluid I drained tonight that I only put in yesterday, was like a metal flake paint job. A worrysome amount of metal I would say. Pump drive knackered Maybe??

 

[jzeiler]

From your pictures it looks like the motor case is on correctly.

OK you said you were originally filling it from the "sprung" fill port. That is the relief valve and there should be a 1/4 inch steel ball in the bottom that the spring rests on. If it fell out and you didn't catch it that could be your issue.

This is a cut away of the relief valve and flow regulator, either can cause an issue if not installed correctly.

 

[Wazza]

As an aside, the Hydraulic fluid I drained tonight that I only put in yesterday, was like a metal flake paint job. A worrysome amount of metal I would say. Pump drive knackered Maybe??

What did the oil look like when you first drained it. Did you flush out the system before putting the last lot of oil in? Some pumps don't like being run backwards.

 

[Wazza]

From your pictures it looks like the motor case is on correctly.

OK you said you were originally filling it from the "sprung" fill port. That is the relief valve and there should be a 1/4 inch steel ball in the bottom that the spring rests on. If it fell out and you didn't catch it that could be your issue.

This is a cut away of the relief valve and flow regulator, either can cause an issue if not installed correctly.

View attachment 181797

If Stu has metal particles in the oil, some of it could be sitting under that ball preventing a good seal.

 

[StuWag]

Thanks John I'm sure the ball bearing is in place, the plug on the flow regulator is very rusted up but it's never been out of its position before. ill try to pop it out and have a look if its all good. Gonna have to drain that pesky oil again!

Wazza, the oil was proper dirty Gray metallic, I didn't strain it and it seemed fairly smooth. the oil I took out yesterday was bad, chunks of metallic flakes, however a friend of mine has had it in pieces in his workshop for a couple of months and I'm not sure what it was exposed to there. it all may have come from that. ill see tomorrow because ill drain it again

There's a lot of corrosion to the cylinder and steel parts on the outer, but inside it looks pretty good. the motor is good, seals in the piston and end cap are new, new cylinder seals and a new Rod. The old tie rod was knackered, rusty but not bent.

I think Im at least in the vicinity of the issue. If anything a pressure relief issue would make sense. Im now a little bit obsessed with fixing this, but work is getting in the way!


Cheers guys

 

[jzeiler]

I had one that passed my rudimentary load test but the customer stated it would not fully lift the bike. He sent it back and put it on my bike and it would not lift it but it still passed my load test. On a hunch I replaced the check ball in the relief valve and it finally lifted the bike. There was a little corrosion on the original check ball. These buggers are sensitive. Since I had to by the balls by the hundred I just put a new on in each rebuild I do now.

 

[StuWag]

I think my Ball has some corrosion on it, and it's definitely bypassing somewhere.
Can I run a pressure test on the pump?
I don't have a clue what pressure these run at. I have gauges that will cope with 20 bar but anything above that is a no go.
I'll pull the pressure regulator and bypass tonight and flush the whole thing out with petrol or something. see how much metal flake there is and pull the pump off. Is there anything I should look out for when pulling the pump apart I may just break the main seal and have a tentative look inside.

Cheers

 

[jzeiler]

Here is how far I go on each rebuild. The pump is rated at 190 Bar and after rebuilding over 75 of these units I have never seen a pump that would not pump. Not worth going into it, just a simple dual gear pump.

 

[StuWag]

Here's the proof that salt on our roads here and the bike sitting with possibly contaminated oil for 9 or ten years has done its worse. One of the studs has corroded so badly that its locked itself into the ally block so ive left penetrating oil sitting in it.

Ive had a look at the bearing ball, its fine, no wear no corrosion
Ive removed the plug that sits over the pressure regulator. should the pressure regulator just release?? I can't see any kind of retainer on it but it's stuck in there good.
It looks to me as though the aluminium corrosion has started to push the thing apart

It may be a combination of issues? I won't go any further than I have to. Im just concerned that ive blown an O ring or seal or something stupid like that.

The one you are working on in the picture above John, Looks immaculate compared to mine‼

 

[jzeiler]

Yeah that is really bad, but it should clean up OK. The flow regulator can sometimes be jammed in there. I usually just grab the little pin with a pair of pliers and work it in and out until it comes free, then lightly ream the hole with a rolled up piece of 220 grit sand paper. The o-ring on the cap is easy to damage and if you do you will have a slight leak there. I used a threaded rod (cutoff screw) epoxied to an old CO2 bottle to use as an insertion tool to hold it in while setting the circlip.

 

[StuWag]

Quick update: I think Ive found a few issues including a physical problem that I could actually see!

Water ingress or Contamination in the oil has rusted the pressure regulator in the fully in position. I tried to grab the pin and wiggle it out but it was stuck fast. As a last resort I put the section of pump into an ultrasonic cleaner. 60 degrees C for 30 minutes and it popped right out to its extended position. It had rust on the piston surface and the surface of the cylinder was corroded.

Also there are locating lugs on the blocks which make up the pump. now these had a build up of aluminium oxide to such an extent that I think it had started to push the sections apart. Causing corrosion on the faces of the sections of the pump block. Ive honed the faces of the sections and removed the corrosion on the pins and corresponding recesses

I'm really hoping Ive caught the problems just in time. Putting it all back together and testing the unit tomorrow will prove the point. couple of pictures below.

Springing in and out nicely, removed the rust with 400 wet and dry.

Cleaned up nice!

 

[jzeiler]

Hope you all the best success on this recovery.

 

[Wazza]

Hope you all the best success on this recovery.

Gee John, you make it sound like he's in hospital.