Fuel leak diagnosed, but how to replace rubber seals? - PeachParts Mercedes-Benz Forum

jbach36 · #1 07-09-2006, 04:16 AM

I took my '91 300d to a shop, it's where the 5 injector lines (?) meet up with the injection pump. (This is my first diesel, and have only had it for 3 weeks, don't know the names of the parts yet). The shop sold me 5 rubber washers and 5 metal washers. I think it's called the delivery valves? I used a star shaped torx wrench to get the 3 collars off, but need to figure out how to do the rest. The shop said that I do not loosen the large nut above the splined nuts at the base. Not sure how to do this. I've also been warned these things are under a lot of pressure. Do you know how to replace these washers? If I knew how to post pictures, I would, to show you the area. How do you post pics along with messages?

Thanks,

Jeff

G Tirebiter · #2 07-09-2006, 12:23 PM

Jeff,

Looks like I have a similar problem with my 95 300d and thanks to your posts I can breath a bit easier knowing that I have a relativily simple explanation for what has developed into a siginificant leak at the top of my IP. I performed a search and found the following link which might help you.

93 300D 2.5L Injection Pump seals
93 300D 2.5L Injection Pump seals - ShopForum

But I can see that removal of spline nuts is a bit of a challenge for my unit as there are no "large nuts" at the base of the spline....must be a newer design that probably requires a special tool to loosen the spline......

P.S. To add pictures, scroll down in the reply window and click on the "Manage Attachments" button. Photos are added there. Be aware that file sizes are very limited so crop and reduce file size before attempting to post.

Guess I will keep on searching or get some guidance here.

Good luck

Brock

Zeitgeist · #3 07-09-2006, 12:47 PM

You need this tool:

You also need this info

Proceed with caution and cleanliness. This is a relatively easy task, but just pay attention to what you're doing. Again, cleanliness is key.

G Tirebiter · #4 07-09-2006, 01:01 PM

Thanks Zeitgeist,

Exactly the info I needed.....looks like I will be adding to my Hazet collection soon

klaus kallas · #5 07-16-2006, 07:41 AM

Wow!

Thanks once again to those posters who take the time to walk the rest of us through a procedure!!

My wife's '97 E300D is leaking (read: pouring!) diesel from the exact same spot. Glad I have a few extra oil-burners around for her while I order the parts for this thing once again....

Klaus

jbach36 · #6 07-16-2006, 11:52 AM

Well, this leak is finally fixed, had to smell diesel and see leaking for about 2 weeks. It was getting pretty bad toward the end, a nice puddle under the car the night before I did the repair.

I appreciated the forum instructions, but it's like steps 2, 5, and 8 were missing, which made the job a lot harder.

Maybe true, the worst part of this job was looking at it, trying to figure it out, then finding out you needed special tools to do it.

For those who have yet to do this "simple" job, here are the steps, as I REMEMBER them, and this was on my 1991 300d 2.5 engine, the leak started with 90k on the engine.

1) You'll need a T30 torx wrench.
2) You'll need the splined socket for your 3/8" socket wrench. Cost $45 or so, then you can resell when done.
3) To do it right, you should have a torque wrench. If not, you can do it by feel.
4) You need 5 rubber washers. The copper washers, as someone else said and so far, I concur, you don't need. Cost of the washers, maybe $3 for all 5.
5) A short handled open box wrench to fit over the 1/2" tall copper nuts at both ends of the injector lines. You can get a complete set at Wal Mart for
$8. I think it's a 12mm wrench, but I'm not sure.
6) If you want your life easier, take photos left, right, and top of the whole area so when you put it back, you'll remember how. If you're not taking pictures, draw how the Torx wrenched collars overlap one another, and note how high or low the STOP button is.
7) CLEAN THE AREA WELL. You don't want debris of ANY kind going into the injector area.

I did mine in a series of wrong steps, so I'm not sure which area to start in first, and maybe there is no right area to start in, but basically, there are 5 areas to start in. You have 1)the injector pump (IP), 2) the copper injection lines, 3) the injectors themselves, and (4+5) two separate brackets that hold them in place so they don't shake. In short, it's the injector lines and the ends the go into and the brackets.

I don't know if the brackets should be taken off first or not, but if I had this to do over again, I think I would start there. You'll see the first bracket holding the first set of 3 lines easily. It's on the manifold, and I think you need a 10mm wrench to get those 2 bolts off. The 2nd bracket, holding the other 2 lines, is not easy to find. Looking from the top of the engine down, it's view is sort of occluded by a small dark plastic coated cable of some type that runs from the mess of wires in front of it, to the engine compartment. You have to get rid of that line in order to get the 2nd set of injector lines out.

To get that line out of the way, you have to loosen (but not take off) what looks to be like the cruise control module, as I think the metal bar from the accelerator goes to it. I'm not sure what the name of the part is, but for now, let's call it the cruise control module. It's sort of square, maybe 3" x 3", and held on by 4 bolts. The upper right bolt of that module will have to be removed, the other 3 loosened pretty well, but not all the way! Why create more problems, right? Once the upper right bolt of that cruise control module is out and the unit is loosened up real well, you can lift that black plastic coated line out a bit, enough to get a 10mm socket onto the bolt under it, and unscrew the injector bracket holding the 2 lines together. (Putting that injector bracket back is a real hassle, so look at the bracket once loose, and see how the clip inside the bracket slides back and forth. It is this clip that the bolt must go through when reassembling).

Once the brackets are loose, now loosen both ends of all 5 injector lines with the short box wrench. Once loose, work the first set of 3 lines so they go back and are out of the way, then do the same with the remaining set of 2 lines.

Once the lines are out of the way, draw a picture of how the Torx collars are, of which overlaps which. Holding the wrench very upright, being careful not to strip them, use the Torx wrench on the 3 collars. They're on very tight for such the small, star shaped bolt that they are. If by chance they strip, you'll have to carefully use a small vice grip wrench on them, preferably in the upright position so as not to torque them sideways. Once loose they come up easily. There's an annoying brown plastic line right in the way of all this, coming from the fuel filter. I don't know if this could be taken out; I left mine so it'd be less potential problems, but it's reeeeeealy annoying working around it.

Take the STOP lever off. It uses maybe a 6mm wrench at bottom, be careful when it comes loose so as not to lose the nut and tiny washer.

Once the collars are out, use the splined socket on the fuel delivery valves. Note how much pressure is used to take them out, and if you don't have a torque wrench, put them back on about as tight as they were to come off. Some on the forums said they used a pick to get the valves out. I tried that, and it was a waste of time for me. Much simpler to take the valve out. When you do, be prepared, as a spring will come out the bottom. So go slowly, take the valve out at as sharp an angle as you can, then horizontal when it's completely out, then upside down, to prevent losing the spring. Once out, take the old o-ring off by hand. Lightly lube the new o-ring in some fuel, and put it on. The threads of the valve might have some debris on them, use a paper towel to clean that off so it goes back in better.

Once the valve is ready to install, take the spring out of the valve, and place the spring by hand directly in the center of where it will go. Then place the valve slowly and directly over it, and screw it down. Do that for all 5, then tighten with the splined socket as tight as they were originally.

Reassemble, making sure to replace any injector clips you may have taken off. The clips are to prevent the lines from clacking together and breaking. The bracket holding the 2 injector lines was the worst to get back. View it ahead of time to see the task ahead of you, noting how the clip slides back and forth. Then hold it up in place and hope the bolt goes through within the first 15 minutes of playing around with it.

Put the lines at the injector pump on as tight as they were, but leave the ones at the injectors only hand tight for now.

At this point, everything should be back to where it was, with the exception of the lines at the injector pump just hand tight. If so, crank the car, will probably take 60 seconds of cranking, to get fuel to come out of the lines. When fuel comes out, tighten the lines at the injectors completely, and you're done!!

Start the car and look for any leaks, which unless you did something really stupid, there shouldn't be any. If there is a leak, find and fix. If no leaks, you should be good to go. Take it out for a test spin. The car might sound a bit funny at first, but after a few miles, any additional clacking should go away, if not, you might have air in the line. To get air out, start the car, and SLIGHTLY back off one injector line at the injector (not at the pump). The car will buckle a bit like you're pulling a spark plug off a gas car, once it does that, tighten and go onto the next one until the problem is fixed.

a2t · #7 07-23-2006, 09:25 PM

Where does one buy such a tool? Are they same for all diesels of this era (123,124,126) or do I need special one for 124?

Quote:

Originally Posted by Zeitgeist

You need this tool:

You also need this info

Proceed with caution and cleanliness. This is a relatively easy task, but just pay attention to what you're doing. Again, cleanliness is key.

tuxbeej · #8 10-09-2007, 04:28 PM

Greetings, eh?

I'm looking to do a similar fix to my car. Are these O-rings you speak of for the delivery valve, then? I've got a link to a part on autopartsonlinecanada
http://parts.autopartsonlinecanada.com/parts/apocanada/wizard.jsp?year=1989&make=MB&model=190-D-002&category=D&part=Delivery+Valve+O-Ring

Is this the proper part? I have to purchase something from there anyway, so including five rings on the order is worth my while.

Thanks!

klaus kallas · #9 10-09-2007, 04:31 PM

Quote:

Originally Posted by tuxbeej

Greetings, eh?

I'm looking to do a similar fix to my car. Are these O-rings you speak of for the delivery valve, then? I've got a link to a part on autopartsonlinecanada
http://parts.autopartsonlinecanada.com/parts/apocanada/wizard.jsp?year=1989&make=MB&model=190-D-002&category=D&part=Delivery+Valve+O-Ring

Is this the proper part? I have to purchase something from there anyway, so including five rings on the order is worth my while.

Thanks!

Yep, those are the correct seals. Good luck!

cornblatt · #10 03-02-2008, 11:31 PM

My car had leaking delivery valve o-rings, so I just did this job using these instructions. Thanks for posting them - they were really useful! I thought I'd add my comments in case they are helpful to anyone else.

These instructions say that you don't need to replace the copper washers, just the rubber o-rings. So, that is what I did the first time.

When I put things back together, I had a much-louder-than-normal idle that pulsated every 2 seconds. Other threads seemed to imply that temporary idle problems were normal after doing delivery valve work, so I drove it for a week with no improvement. The idle was so loud it was embarrassing.

I took it apart and did the job a second time, replacing the copper washers this time around. When I got it back together, the idle was no longer loud, and it was very smooth again. It ran great immediately upon startup.

Upon closer inspection, the old copper washers had miniscule but noticeable indentations in them from when they were installed previously; perhaps they don't always seal right if reused.

A set of new copper washers cost me under $5 at the dealer. I know that others have reused the old ones successfully, but you risk doing the job twice if you don't replace them. There's nothing worse than re-fixing things you already fixed. Put these on your shopping list.

Also, the o-rings tend to get caught in the threads when removing the pressure valve holders (see photo taken during removal). The threads are pointy and cut into the o-rings. This means you've got one installation attempt per o-ring, since they are destroyed upon removal. Have extras on hand if you end up redoing the job.

Before you put the pressure valve holders back on, be sure that the components underneath them are perfectly centered in the hole. They can slide around. Resist curiosity and don't remove anything other than the spring and copper washer.

There's supposedly a special torque procedure for reinstalling the pressure valve holders. It's 30Nm, 30Nm again, then 35Nm. I could not find consistent information on the forum as to whether you back off / loosen between these steps, or just tighten only. I decided to tighten only.

On the OM601, if you have a small torque wrench, you can access everything to do this job simply by removing the air filter box. It may look like you need to remove the intake manifold, but you don't. You also don't need to remove the stop lever.

The special socket is p/n 617-589-01-09-00.

There are also a couple of good DIY articles on this job (click the "DIY Articles" tab at the top of the page) so be sure to check those out too!

compress ignite · #11 03-03-2008, 01:23 AM

tuxbeej,

Pictured are the Delivery Valve Copper Washers for My 300D 2.5 Turbo.

Ask your parts people for the correct application for your 201.128

As cornblatt said you'll be glad you did!

tuxbeej · #12 04-01-2008, 12:58 PM

Thanks, compress. I didn't follow up on this thread for a little bit after I bought the O-rings, so I missed the note about buying the washers.

The IP has been dry on top ever since I changed the O-rings a month ago, so I think I dodged the bullet. We'll see how it does after a few more months. In the meantime, I have to replace one of the metal injector lines on injector #4 as it started spitting fuel like a fountain during a recent road trip. It's stuck in Calgary (while I'm in Edmonton) so I'm trying to get my parts together so I only have to bus it down *once*. As long as I can get it back to Edmonton, I'll be happy (and I can change the other lines a little later).

bobodaclown · #13 12-28-2009, 04:20 PM

Nice write up. Didn't take all that long at all. It's pretty straight forward. Didn't need to remove the intake. But did remove the cruise control actuator motor. (Took of the 4 bolts and set it down. Removed the 1 bolt to move lines 4 and 5.

OAbrey · #14 04-21-2010, 02:27 PM

Was looking at this job, and wasn't sure if I needed to remove the intake manifold to do it right.

Corn, I appreciated your explicitly referencing that.

Did you remove the injector lines entirely? Inc off the injectors.?

Now, off to take some pictures and dive into the job.

cornblatt · #15 04-21-2010, 03:03 PM

Quote:

Originally Posted by OAbrey

Did you remove the injector lines entirely? Inc off the injectors.?

Yes, the injector lines have to be completely unfastened (i.e. un-fasten at both ends and remove the plastic retainer clips) so that you can move them aside to access the top of the IP.