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Need help with '86 300GD water pump

2805 Views 12 Replies 4 Participants Last post by  T-Man, 
T
3
I'm having issues getting my fan/pulley to get to my water pump. I don't have the typical 4-bolt fan system. I have A/C, so there's the bracket thing. No big deal.... The issue is getting the clutch/pulley assembly off of the water pump. has anyone heard of or seen this fan set-up? It is Behr/Mercedes, but maybe not stock....All I see is a huge "nut" to put a LARGE Channel Lock on and use the weep hole to keep the pump from spinning! Sound right at all?

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4x4abc
T-Man

it is a stock set up all right. A big channel lock (I use an 18" long CL) and a long pin (too brittle and it'll break - too soft and it'll bend) in the weep hole will do the trick.

Harald
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T
Thanks Harald, hopefully someone has one of those pumps lying around. The bearing is definitely shot and I don't think I'm up for rebuilding it. Not crazy about that whole set-up, quite frankly. That A/C bracket is a pain....and I like the 4-bolt set-up better on the fan.
Thanks again, Tristan
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Dai
Tristan,
I have not had to face this problem in my G yet but when I do I'm going to the 4 bolt pully common to 123 chassis D's. I keep one of this style pump around because seal failure is usually the problem Several GD owners have eliminated the fan and clutch, bolted up the pully and used an electric fan in front of the radiator. I intend to try this and use a fan from a 123 chassis A/C radiator. Should be pretty easy to make work and will simplify things as well as buying back a little power. The pump will be a lot cheaper too. Warren has this setup and says it works well. With the A/C bracket setup you have it's hard to avoid breaking the seal on the little gasket between the head and the housing the pump bolts into. Good luck with that. I am now a big fan of Hylomar.

-Dai
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T
Thanks Dai,
I like the idea! Although, there are a couple issues I see with that conversion. I would definitely have to use some kind of spacer between the A/C bracket and the pump housing to get a solid connection. Also, does the 123 pump/pulley assembly line up with the existing belt path? Could be an alignment issue there. I'd love to see what Warren has done! I already have an electric fan installed that looks like it's from the 123 A/C fan like you said, so that's good. Is that fan alone enough to cool the beast on a long grade up to Tahoe? Hmmm.... Oh, Hylomar? Please enlighten...
Thanks, Tristan

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Dai
I hope Warren and others who have done this contribute here. It looks like a housing off of a standard 617 or turbo motor will be needed due to the difference in bolt pattern on the pump. From your photo I don't see the bolt holes around the base of the G pump like the standard diesel coolant pump on the right. How stupid is that? As I said I haven't had to service my pump yet so haven't seen the problem. I may have access to some pump housings and if I can help you let me know. I bet I can come up with one for you inexpensively. And a standard pully for that standard pump. I don't think there is a belt path issue except for the double pully belt setup that was used for a while. My wife's TD has that silly feature. There are others that have done this, Greeny in England has some posts some time ago about this. Try the search feature in the header of the forum or go back in Greeny's posts. I think spacer bushings will work for the bracket, my memory of this on a 220D air conditioner bracket had some steel bushing spacers that trapped the pump housing against the head. What a pain! Email me if you need help on the parts. A friend has many dead motors in his shop and will help I'm sure.
Hylomar is a sealant that stays pliable but seals beautifully. A good NAPA store should have tubes of it under a NAPA number. Perfect for the pump gasket and the little gasket on the back side of that housing. I'll come up with the number and post it later today. Best of luck,

-Dai
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T
Ahh, yes! Good sealing compound is a good thing. I think I'm going to try this conversion. The pump housing has the same bolt pattern needed to use the 4-bolt WP, you just don't use them with the G pump. I've got the gaskets and the 4-bolt WP. Now, all I need is the pulley and fan and some kind of shim action for the two bolts that go through the A/C bracket and pump housing. I think the thermo coupler on my stock fan is problematic anyway. It runs excessively in my opinion. Even when the temp guage is under half, it likes to run. I'll probably be able to locate what I need down here, but if I need help I'll let you know.
Thanks again, Tristan
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Dai
Good news about the housing. The waterpump on the G diesel has an odd mount compared to the all of the other MB diesels. I don't understand the deviation from a proven design. It makes the part expensive, difficult to get and much harder to service. Big nut, huge channelocks, and a punch through the weep hole? I'm going to convert it just to 86 that stuff!
The Permatex Hylomar HPF number is 25249. I don't know if that relates to a Napa number or not. In the UK it's known as Hylomar Blue. I think it's Really Great Goo.

-Dai
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T
OK! If anyone is interested, I have completed the conversion to the standard 4-bolt WP/Pulley/Fan Assembly. It's fairly simple overall: The A/C bracket has two bolts that go through water pump housing and into the head. When you put the new pump in make sure to fill in the gaps created by the absence of the old WP's flanges. I did this with five thick washers equalling the thickness of the flange. You also need to get shorter bolts for the two others that go through the pump housing. Grab your new pump and add 3 new 10mm bolts for that. (The housing already has the holes you need, so don't worry about drilling/tapping, etc.) Use some Hylomar on both sides of the gasket and bolt her on! The only cheesy part of this process is that you need to shim the pulley itself out 1/16" +/- to get belt path properly aligned. The new fan is quieter, a little smaller and certainly simpler. I think this is a worthwile conversion if and when your pump goes bad. Europa quoted me $350 and a two week wait to get the original from Germany. I got a brand new Japanese pump for $56 and the pulley/fan assembly from a junkyard for $50! Do the math...
Cheers, Tristan
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Dai
Good it worked out without too much trouble. Did you use the fan clutch for the 123/126 vehicles? Strange that you had belt path issues. I installed an aftermarket alternator on my G specified for 123/126 diesels and it was an exact fit with no modification needed to align the belt path. What application was the waterpump you used made for? Was the pully from an early diesel? Thanks for posting the follow up. Pumps fail and standard MB diesel waterpumps are an off the shelf item in my area for a reasonable price. Could you post an "after" photo when you have time?

-Dai
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M
Tristan did end up doing the W123 wasserpump conversion, and it seems to have worked out well. He's real fluent now in changing them out, since he had to do it 3 times. 1st time we thought it was the seal, not the pump, ended up the pump was faulty (hence leading to this thread)

second time I gave him a W123 pump I had that I thought was good, and I am sorry to him that it was not!.

So third time around, on Sunday night, we swapped in a new W123 pump, new bolts, used the sealant you suggested Dai, and wholla it is lovely.

Tristan had to shim out the pulley a little bit but other than that the only difference is a slightly smaller fan.

oddly, we found that most 280's (G or car) have the same setup, but use a metal fan vs. plastic in the 300D / 240D / 300TD.

Anyway, $50 at the junk yard, and he was set.
so far so good.

-mserpe
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M
oh and also, with the W123 setup its easier to access so no radiator removal is required
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T
5
Thanks Mike for your kind words and thanks Dai for your support! The pulley and clutch/fan assembly were from an early 80's 300D junker The A/C bracket and most everything else looked exactly the same as my G. The belt width is slightly different, but all seems to be just fine. Fingers crossed....
Thanks again, Tristan

Here are some after pics of the now less leaky and cooler 460:

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