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Hydraulic fluid leak - in front of rear tire

20K views 63 replies 8 participants last post by  ErdeM3 
#1 ·
I came out to find a puddle behind my drivers door/infront of my rear tire and wondered what it was... until I started to put up the top and knew exactly what the fluid is.

I searched and found all the PDFs on the 6 cylinders, yet would prefer a DIY if anyone has replaced the main or storage compartment cylinders - especially since the PDF for the main cylinders starts with "remove convertible top" :banghead:

I am going to assume it is the drivers side main cylinder that is leaking, yet need to check it - yet how? Its not the bow cylinder since the top would be stained. Its not the pump as I took out the trunk liner and inspected it. I don't suspect its the storage compartment cylinder as the leak is infront of the rear tire and the cylinder is behind the rear tire... right?

Help and pictures would be appreciated!
 
#2 ·
:( The drivers side main lift cylinder is leaking, there's a puddle of hydraulic fluid (mineral oil?) under the main lift hinge.

I can see why the first step is "remove convertible top"... so HOW? I see the 2 quick disconnects for the hydraulics, and 3 nuts per side anchoring the top... yet I am guessing there's at least a couple more nuts I cannot see without removing the trim... so HOW? I would like to get it done while the weather is good, so any help would be greatly appreciated! Thanks in advance!

This will give me an excuse to ride my motorcycle that hasn't seen a lot of use this summer since getting a convertible :)
 
#7 ·
Update:

I decided to tackle this in stages, which was a waste of time considering how easy its been. I've spent about 3 hrs total: 1.5hrs to remove the rear trim and trunk liner, 1.5hrs to remove the entire top, remove the main lift cylinders, and reinstall the top (since its my DD and its pouring rain outside). If I had done it all at once, and didn't get stumped on a couple things, I would've been done in < 2hrs. Notes (I'll try and take pictures when I put it all back together):

1. There's a trick to manually putting the top down/up. I noticed the first hinge (closest to windshield) would not move at times. Finally figured it out. The latches that close the top are also connected to latches that prevent the first hinge from moving. If you're having trouble getting the top to open/close manually, turn the crank at the windshield and watch the first hinge to see the latches move. This probably cost me 30 mins to figure out, and I felt dumb after.

2. Removing the rear interior requires the top to be down to pull the side trim up. So you might as well remove the rear trim and top at the same time. I did this over a couple days, removing the rear trim one day and removing the top this morning. This probably cost me 30 mins.

3. Removing the entire top is very straight forward. Here's a tip:
- The latches for the storage cover are connected with a cable. The cable must be disconnected to remove the latch, and the latch must be removed to remove the top. Detaching the cable required removing a c-clamp and pressing 2 tabs on a square retaining block.
- A set of angled pliers is an asset here as the space is tight.

4. Removing the main lift cylinders is super easy, just follow the instructions in one of the PDFs posted on this site.

5. I pulled all the fuses for the "power top" only to find out a couple fuses are shared with DSC and ABS (12 and 42, I think - definitely double check). The pump runs at startup to pressurize the system, which I don't want since the lines are disconnected. I'm hoping that fuse 35 (the big 50 fuse) is enough to cut all power... I guess I could measure the voltage at the pump to confirm.

6. I'm positive its going to be harder to put this back together than get it apart as some of the spaces are very tight. It was easy to undo lines, clamps, ... in those spaces, attaching them might be another story.
- I'm not sure how to get the main lift shock back in, its very firm and won't compress by hand. Will probably have to attach the bottom of the shock with the top out of the car, then attach the top of the shock with the top installed and extended.
 
#9 · (Edited)
I think I have another thread documenting where I'm stuck. It was definitely easy to reinstall the main lift cylinders, went faster than removing them.

I'm stuck at reinstalling the gas shock on the passenger side. It cannot be compressed by hand and is ~1/2" too long when the top is fully extended. Someone that performed the same repair commented that it took force to reinstall the gas shock, so I have a big F clamp to try when I have a free weekend or waiting till someone else attempts it and finds a trick to reinstall the damn gas shock!

No pics unfortunately. The pdfs have pics that are sufficient.

Sent from my Nexus 7 using Bimmer App
 
#10 · (Edited)
Update:

Got the gas strut on: http://www.e46fanatics.com/forum/showpost.php?p=15171727&postcount=12

Top is reinstalled, pump filled, ready to go... yet wow I have the dreaded flashing red light. Checked:
- Fuses are good
- All electrical connections reconnected (2 on each side, 1 main connection)
- Storage compartment down
- Already fixed the crimped wire once, hopefully its not that again.

To be clear, the top is manually closed and pushing the top open button does nothing. No noises, no movement, nada. :(

Need to search and find a good diagnostic procedure for this. Any help is appreciated.
 
#11 ·
If I disconnect the CVM plug the flashing red light stops, so I assume that's where to start. Quickly measured the continuity of the pins and found the cowl lock and unlock sensors do not have perfect continuity so I am going to have to revisit the bend in the harness tonight.

I wish there was a way to read the CVM codes without visiting a shop.
 
#12 ·
Soldered in new wire for all 4 leads at the bend to be safe since 3 wires were close to breaking, yet all 4 showed continuity to the plug :(. Thus I suspect something is wrong between the bend and the latch, so I'll have to remove the latch cover to investigate.

Also found a problem with the storage cover latches. They are controlled by cables which need to be pulled out of the way to remove the top. In doing so they became tangled at the motor not allowing the latches to work properly.
 
#13 ·
For myself... I had to plug the scanner. We removed all the codes.

Than I started the car. Windows down, top down... I pushed the closed button and it all started moving and closing.

From that moment we saw that it was not the cylinder the problems, but really the hydraulic lines that ran from the control unit to the main left cylinder! Without that trouble... everything would have been fine!
 
#14 ·
Hydraulic cylinder upgrades - OEM used inferior seals on all six cylinders

Wow, three Canadians already in the same thread, who have used our services - thank you for sharing!

Seb_323ci_2000, you did not waste your money on having your main drive cylinders (aka main lift cylinders) upgraded by us - they would have failed sooner or later, and now you should never have to worry about them again.

The OEM cylinders have cup seals made of Polyurethane in them, which have a fairly limited service life. Top Hydraulics replaces them with cup seals made of a far superior material, which should last several times as long as the original seals under the same conditions. That means, we make your old, leaking cylinders better than new ones for a fraction of what you would pay your dealer.

gbakerkingston, you mentioned it taking three weeks to get the cylinders back. I think over 90% of that was shipping time. We now average about a one-day turn around time on BMW E46 cylinders, although we wouldn't promise it. ;-)

Klaus
 
#15 ·
Klaus: the time delay noted was total turn around time from my removal of the cylinders, using cheapest international ground transportation to the west coast to your shop, your shop time and cheapest international ground transportation back to the east coast. The car was in winter storage, so speed of repair was not material. Readers can be confident that if turn around time is important, Top Hydraulics can accommodate their needs satisfactorily.
 
#17 · (Edited)
shipping bow tension cylinders to Canada

Mike,

looking forward to making your cylinders better than new ones, as well! Shipping from Oregon to Montreal by USPS Express Mail usually takes 3-4 days. When can ship one pair of cylinders in an Express Mail envelope (with a shipping box inside the envelope), or all six cylinders in an Express Mail Box. The cheaper Priority Mail service is a bit unpredictable, as far as transit time goes.

gbakerkingston, I hope you were not concerned about my previous clarification of our turn around time; I much appreciate your kind words and only wanted to avoid concerns that others might have had on how long it will take to get their cylinders back.

We will soon be offering "up-front shipping" service, where we send out cylinders from our stock first (at a slightly higher price plus deposit), and rebuild your old cylinders for the next customer after we get them back from you.

Klaus

www.tophydraulicsinc.com

part numbers for reference and as keywords:

Bow tension: 54 34 7 025 600, or 54 34 7 025 599 for LH only (aka hydraulic cylinder for clamping bar p/n 54347025600 or 54347025599). There was a design change at some point that requires both cylinders to be exchanged together, i.e., you cannot have an early version bow tension cylinder on one side and a new version bow tension cylinder on the other side. The change relates to the fittings on the hoses going from the RH cylinder to the LH cylinder. Pairs of old cylinders and new cylinders interchange without any problem.

LH soft top lid or tonneau cover cylinder: 54 34 8 243 269 (aka hydraulic cylinder for storage cover p/n 54348243269)
RH soft top lid or tonneau cover cylinder: 54 34 8 236 956 (aka hydraulic cylinder for storage cover p/n 54348236956)
(switch for LH cylinder: Hall sensor 54 34 7 043 558 and bracket 54 34 7 042 482)

LH or RH master cylinder or main lift cylinder: 54 34 7 025 593 (aka main drive hydraulic cylinder p/n 54347025593)
 
#18 ·
Update:

The flashing red light o'death was the hardtop install kit missing. I unfortunately sold it before knowing my car was coded to require it, so the CVM was complaining the sensor that detects the hardtop is installed was malfunctioning. The hardtop kit is $140, yet I really only needed the sensor. I found out the hall sensors are all the same, and only $23: http://www.ecstuning.com/Search/61318378940/ES168252/

With the sensor hard wired in the top finally came to life... only to stop after unlocking from the wiindshield, so I must have broken a wire in the harness when replacing the main lift cylinders. Probably when trying to force the stupid gas strut back on.

Also installed the rebuilt storage lid cylinders Klaus rebuilt for me! Thanks Klaus! Re-installation took about 30 mins.
 
#19 ·
#20 ·
cut hydraulic line/hose

Bummer! BMW uses good material for the hydraulic lines, but it is still important not to get the lines kinked or cut. Fortunately, Top Hydraulics is manufacturing hydraulic lines, and we can make one for you once we know for sure which one you need. We currently make the BMW lines out of the same exact material as BMW.

It's too bad that you have to take the top off again to get access to that particular spot. Look at the bright side: you are able to figure this out by yourself, and you can help out many future readers by documenting how to do the job perfectly! :)

Also, if your car were a Bentley Azure or a Rolls-Royce made in the late 90s, you would now have to replace all 26 (!) hydraulic lines, because they were made of a material that disintegrates about as quickly as the cylinder seals...

Klaus

www.tophydraulicsinc.com
 
#21 ·
It's too bad that you have to take the top off again to get access to that particular spot. Look at the bright side: you are able to figure this out by yourself, and you can help out many future readers by documenting how to do the job perfectly! :)
My buddy and I have gotten so good at this that it took about an hour to get the top off, line removed and top reinstalled. :)

There was so much hydraulic fluid that we didn't take pictures. Now that its cleaned up we'll take pictures when reinstalling.

Also, if your car were a Bentley Azure or a Rolls-Royce made in the late 90s, you would now have to replace all 26 (!) hydraulic lines, because they were made of a material that disintegrates about as quickly as the cylinder seals...
If I owned a Bentley or RR I would probably not be DIYing to save a few $$$ :) Holy crap, $4K for hoses! http://www.tophydraulicsinc.com/en/33-rolls-royce I'm going to buy some lottery tickets!
 
#23 ·
hey guys, I got a similar issue on my 06 e46- m3 vert.
there is a cut on one of the small lines going from the valve block to a cylinder on driver side.



I can not see the number on the line but it is the middle one on valve block. I talked to Klaus earlier and I will order the line once I am sure which one it is but then the toughest thing, how to replace the line?

taylor192, did you take the pictures while reinstalling?
 
#24 ·
How do the hydraulic lines get damaged?

there is a cut on one of the small lines going from the valve block to a cylinder on driver side.

I can not see the number on the line but it is the middle one on valve block. I talked to Klaus earlier and I will order the line once I am sure which one it is but then the toughest thing, how to replace the line?
ErdeM3,

since I don't have access to an E46, I cannot tell which line is cut. I hope that taylor192 can already tell from the photo.

After taylor192 posted about his problems with a cut line, we have had a number of inquiries about replacement lines for E46 convertible systems. See also http://forum.e46fanatics.com/showthread.php?t=966815 and http://forum.e46fanatics.com/showthread.php?t=979101. I am trying to gather some statistics on how these lines get damaged - whether they simply wear from repeated strain near the mounting points, whether they get cut by sharp foreign objects like glass, or whether this happens almost exclusively after people replace their leaking hydraulic cylinders and accidentally pull too hard on the lines or accidentally cut them with a sharp tool. I actually have a hard time believing that tempered glass falling onto the lines would cut them, but it could happen if a sharp object was temporarily wedged in the wrong place and the line kept on rubbing on a sharp edge.

Has anyone worked on the hydraulic system of your car before, or has there been shattered glass falling into this area?

Klaus

www.tophydraulicsinc.com
 
#25 ·
Has anyone worked on the hydraulic system of your car before, or has there been shattered glass falling into this area?

Klaus
I don`t have that information but dont think so. the line looks messy just because i tried to seal it, patch it :) which of course didn`t work.
Also, It cant be the glass falling etc cause, area where the cut is, covered by a metal frame.
I guess, this one is simply wear from repeated strain near the mounting points...
 
#31 ·
While you are replacing the line, have Top Hydraulics upgrade all hydraulic cylinders



ErdeM3,

strain near the mounting points is indeed my suspicion for most E46 hydraulic line failures. We have seen that repeatedly for the bow tension cylinders and for line #23 going from the valve block to the main lift cylinder on the right side.

I would suggest that you have us upgrade all six of your hydraulic cylinders before they fail, which could be any time soon. The original seals in the hydraulic cylinders decay with time - they even have a limited shelf life when they are not installed in a cylinder. That decay gets accelerated by heat, which you have plenty of in Texas. All six cylinders use the same seal material, and all of them will fail eventually. It's a shame that the OEM saved a little money on the seals and didn't pick the proper material. Attached find a picture that shows the seal decay progress. Even the first stage of decay will leads to the cylinders leaking slowly, and you certainly don't want to have any hydraulic fluid dripping onto the tonneau cover. :tsk:

Klaus
 

Attachments

#26 · (Edited)
Update:

Tested line #21 and it did not leak despite being bent. Damn, that would have been an easy fix.
Found line #23 was split at the first bend. Looks like it doesn't have enough slack from the valve body to the first bend, so over time it eventually splits along the outside. Line #24 has lots of slack and is fine (line #23 and 24 run beside each other from the valve block to the passenger main lift cylinder).

I took photos of where line #23 routes at the valve block and first bend, yet after that it runs along one of the tension bars so it is next to impossible to take a photo in places I could barely reach. It is fairly easy to remove except for 2 spots.

Starting at the valve block with the top down and storage lid propped up:
- Disconnect line #23 as all other lines are disconnected: Pull the plastic retainer, turn the metal retaining, pull line out. This can be done with bent pliers without removing the top from the car.
- Remove 4 #20 torque screws holding on a plate that protects lines #23/24 and the harness at the first bend. Remove the plate. Note one of the screws is shorter than the rest.
- Put the top up at this point. Helps to have the window portion on an angle, and the top bent back from the windshield to allow the fabric top and headliner to be loose. I'll take a picture to demonstrate.
- Follow the line around the bend and up the tension bar. From the "c-pillar" the 2 zipties will be visible and must be cut.
- This is where I ran into difficulty. The lines pass under a plastic cover (circled in red) that is riveted to the tension bar. The opening is barely big enough to get the lines through, nevermind the 90 degree bend fittings on the end of the lines. I am going to experiment this weekend with how to either run the line under the tension bar (risking getting pinched at the joint) or over the tension bar (visible through the fabric when the roof is closed) or try a fitting with 30-45 degree bent to see if it'll fit. I think a slightly bent fitting can be routed under the cover.

Removing the plastic cover is out of the question. It would require pealing back the fabric top to drill out the rivets. Removing the fabric top is a 10hr+ job, so even pealing it back would be more than a few hours.



- Follow the line across the horizontal portion of tension bar. The lines are clipped in 3 places, all visible by moving around the fabric top and headliner.
- Repeat on the other side until the line terminates at the main lift cylinder. Disconnect from cylinder (see my DIY).

Again, all of this can be done with the top in the car. It is actually easier since the top has to be articulated in different positions to remove line #23.
 
#28 ·
Klaus, do you know of any shops that replace the fabric top on the e46? I would really appreciate high quality photos of the area circled in red so I can get a better idea of how the lines are routed in this area.

I'm going to ask around Vancouver, maybe a shop here is in the process of replacing the fabric and I could sneak in to grab some photos of the frame.
 
#29 · (Edited)
Finding the least labor intense solution for installation of hydraulic line # 23?

taylor192,

thanks for the update. I'm looking forward to learning how your experiments turn out this weekend - this could save many E46 owners a lot of money. Hope that just (very carefully) bending the 90-degree fitting to an almost straight shape will work out. You are bending a steel tube with pretty thin walls, but the bending part is possible. I just hope that it will be easy enough to pull it through the plastic cover at that point. One of the problems might be that the connector will be pretty long once it is straightened out. It will certainly help to have a slightly longer line than the original.

We could also make a totally custom part that might save a lot of labor upon installation and be worth the extra production cost: Split the line into two sections with short, straight connectors that both plug and clip into a custom made union of about 5/8" diameter and 1" length. There should be room for such a union somewhere. Check out the picture below for what that union could look like (and imagine lines clipping in from both sides). The union would be the aluminum block on the left side of the photo. Mirror image the photo, attach it to the left of the current photo, and you see the intended setup.

Klaus

www.tophydraulicsinc.com
 

Attachments

#33 ·
That would make this a really easy repair. Cause of the design of the "c-pillars" that angle out at the bottom, there is a lot of room for that union to be ziptied along the vertical section of the tension bar without interfering with anything, and be mounted in a spot that does not bend, so little chance of fatigue/failure.

The extra cost would be well worth it! This goes from a job requiring removing the fabric from the top and removing the top from the car... or rerouting the line in a way that may eventually fatigue and fail... to a DIY in about an hour (after removing the rear interior, which would be required to access the valve block from the top).

Very interested! You just made my day!!! I was feeling down this past week as this repair was becoming a nightmare. Thanks for the motivation to keep going!
taylor192,

the forum is very lucky to have you doing this, and I'm glad to hear that the custom union might be solving a huge problem.

May I suggest that you leave the old line routed through the bracket, so that you can tie the new one to it and pull it through?

I just need to know how much longer the new line assembly should be than the original line #23, and how far from the shorter end the union should be placed.

Keep your eye on the ball - you're almost done, and you saved a boatload of money! :)

Klaus

www.tophydraulicsinc.com
 
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