Author Topic: WUR Rebuild  (Read 606 times)

daantjie

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Re: WUR Rebuild
« Reply #15 on: 24 July 2019, 01:24 PM »
I found this schematic ages ago, and I am only really certain of the one marked as 0438140010, but this may help identify the type you have, and the correct vacuum connection for each:
Daniel
1977 450 SEL 6.9 - Astralsilber

Mattr

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Re: WUR Rebuild
« Reply #16 on: 24 July 2019, 03:01 PM »
I found this schematic ages ago, and I am only really certain of the one marked as 0438140010, but this may help identify the type you have, and the correct vacuum connection for each:
I was using the part number off the top of the WUR itself. Bosch issued about 20 different part numbers, despite there being only 4 different varieties? I think it has to do with engine displacement, or specific vehicle application, or somesuch. I haven't rooted that out yet, which makes me a bit hesitant to try swapping in a WUR with a different part number.

Oh, and I own the book that's taken from, if you ever need more information on our fuel system. :)
1976 450SE 6.9 FrankenBenz (#2288?)
1977 450SEL 6.9 #2333

Diesel 617

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Re: WUR Rebuild
« Reply #17 on: 29 July 2019, 05:04 PM »
For WUR, Fuel Distributor and injectors testing, I can only recommend  CIS flowtech. They do excellent work, within 1 week turn around time or sooner ( I was waiting for the diaphragms to come in). I think they charged about 340$ for the wur and 25 for shipping and handling and about 560 for the fuel distributor. These parts are rebuilt as though they were new from the factory and worth the expense, all the gaskets are replaced and everything is polish and cleaned looking like new. A+ service.
X3 1980 300SD Blown Heads, trans -Retired
1980 450SEL Parted out
1980 450SEL to Diesel Parted Out
1979 280SE Euro Spec Cloth Seats: Needs Rebuilt head and WUR
1979 300CD Daily Driver


Inventory of w116 Parts
https://www.ebay.com/usr/vintagepartsandstuf

jjccp

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Re: WUR Rebuild
« Reply #18 on: 31 July 2019, 06:43 AM »
Just used CIS flowtech about a month ago for fuel distributor and WUR on my 6.9. Quick turnaround. My mechanic said they did good work. He also replaced the injectors and my engine runs great.
1977 280 SE
1979 6.9 #6846

Mattr

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Re: WUR Rebuild
« Reply #19 on: 01 August 2019, 09:39 AM »
Saying the the double rubber diaphragm rarely goes bad is a surprising statement.  It is in fact usually the small round rubber diaphragm in these that fails.  The symptom them is low <1.5BAR control pressure even when warm.  Most aftermarket suppliers of diaphragm kits don't offer the double diaphragm units because they are technically difficult to manufacture.

The double rubber diaphragm wurs are far more prone to problems than the simpler single rubber diaphragm units in 4.5, 6.9 etc

What I meant by this (which, my bad for not being more precise, too many diaphragms, not enough explanation) is that the guy from Salvox said that the lower rubber/steel diaphragms are very rarely problematic, it's almost always the upper round diaphragm which goes bad. That's why they don't bother with a kit that replaces the lower one. I did find such a kit for $125, and will contemplate pursuing it if I'm still having issues after replacing the upper.

That's all on hold, at the moment, though, since I've a C220 to get back to being road worthy, and the starter on my 6.9 caught recently, so I need to get it on the lift and replace that, then worry about the WUR.
1976 450SE 6.9 FrankenBenz (#2288?)
1977 450SEL 6.9 #2333