I am trying to find just the bearing. So far I have been able to find some decent quality Nachi (Japan) bearings on ebay for under $10, but I'm not certain they are

I just used a Nachi to fix an idler pulley bearing on my Jetta and it was nice

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80 300SD (129k mi) 82 240D stick (193k mi)77 240D auto - stick to be (153k mi) 85 380SL (145k mi) 89 BMW 535i 82 Diesel Rabbit Pickup (374k mi) 91 Jetta IDI Diesel (155k mi) 81 VW Rabbit Convertible Diesel 70 Triumph Spitfire Mk III (63kmi)66 Triumph TR4a IRS (90k mi)67 Ford F-100 (??)

I thought Nachi were Chinese??. I can’t comment on them.

The bearing for W115 is the same - #626.


Junk #626 bearings are very common and as it is crucial that you use only “Precision” grade bearings I advise that you order ONLY from a specialist bearing/seal store. Check the catalogue with the salesman – they should be under $10. If you have trouble locating one, phone your local MB agent and speak to the workshop manager, he will put you in touch.

Order only reputable brands. I suggest SKF, FAG, NTN or INA who conform to ISO 9001. I have always used NTN as I prefer the steel cages. I have always had to order for #626 open 6 ball – they should have them the next day. They are sure to have #626 8 ball (light duty) and 6 ball sealed or with metal dust covers in stock so don’t let them tell you they are suitable or suggest removing the covers.

Bearings are graded broadly into two categories, “Precision” and “Semi-Precision” (better specified ‘Non-Precision” in my opinion). Precision bearings are designated Grade G100 down to G3 – the lower number being highest precision. Semi-Precision go from grade 100 to 1500. If any of the above brands are stamped on the bearing it will be G50 which is a benchmark for reputable brands.

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Beagle

To wrap this up from my side, one last tip I forgot to edit into Post#1 - It could save some a few bucks!.

The current price of the piston seal kit is $171 (June 2012). If the seal is scored you can turn the Teflon band inside-out and restore a pristine seal. It is important then to replace the seal with the same edge to the inside as the seal band is very slightly coned by the O-Ring pressure. The last time I changed the bearings on mine I did this and it worked perfectly!

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Beagle

Bumping this thread for some help.


I have the vacuum pump off my 240d. Thought I'd replace the pumps bearings while doing the water pump. Well.. I've gotten two wrong types of bearing from my local skf distributor. Both were '8' ball types. I even printed out the last to paragraphs from the OP's first post and brought it with me the second time. The sales guy doesn't think it's an issue, but everything from this thread says different. I'm leaning on the guy does know bearings that well. I know I don't.

My questions. Does anyone know of an online source to find these 6 ball 626 bearings? Anyone know a part number for skf bearing? Maybe something to tell this sales guy what to look up? It might just be time to find another distributor..

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Dave

1985 190D 2.2 auto--gone
1975 240D 4-speed--storage
1985 500SEL--daily driver
1985 300TD--bad rust, soon to part out...
1982 300SD--waiting on engine from RD
1984 190E--storage
1996 Dodge 2500 Cummins--daily driver

There's been a recent discussion about that here =>

Will these bearings work for a vacuum pump?

I think that the most important thing is to get the "precision" bearings and not worry about 6 or 8 balls.

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1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

Amount of time the vacuum system holds before rising to atmospheric pressure is perhaps a good yardstick to use. If the door locks still work for a couple of days after shutdown the system is probably reasonably tight or tight enough.

There is a vacuum storage or accumulator in that circuit to consider in this approach. In most case this is a relatively inexpensive system to restore integrity to if indications are it needs it.

Great post. IMO, one of the most important facts to come out here about VPs is to keep the pump from working over time by fixing the leaks.

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1985 Euro 240D 5 spd 140K
1979 240D 5 spd, 40K on engine rebuild
1994 Dodge/Cummins, 5 spd, 121K
1964 Allice Chalmers D15 tractor
2014 Kubota L3800 tractor
1964 VW bug

"Lifes too short to drive a boring car"

Are these prices/part numbers for the archaic 617 pumps????

I have the very early 617.950 engine in my 1878 300SD

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Did you just pass my 740 at 200 kmh in a 300SD?????

1978 300SD 'Phil' - 1,315,853 Miles And Counting - 1, 317,885 as of 12/27/2012 - 1,333,000 as of 05/10/2013, 1,337,850 as of July 15, 2013, 1,339,000 as of August 13, 2013



100,000 miles since June 2005 Overhaul - Sold January 25th, 2014 After 1,344,246 Miles & 20 Years of Ownership

Well parts for a 1878 sd are really scarce to start with. I would not worry about their cost as you are not going to find any. You not only get the highest fuel milage for type but must have the earliest known 617 in existence.

Actually there are many old earlier vacuum pumps around that at worse need a new diaphram and valves perhaps basically to choose from. Not really expensive to recondition. The really more difficult era started with the later introduction of the piston type vacuum pump on the 617s as Beagle is reffering to. The nice catch of turning the seal inside out by Beagle to present a new wear surface I will remember. These costing more to recondition than the early diaphragm units. Followed by the type used in the 603s and their miserable bearing issues.

I got a rebuilt diaphragm unit several years from a guy that did a total rebuild on his engine and accessories. Unfortunatly he did not use new oil hoses to the oil cooler. That event must have really hurt both financially and mentally.

I'm trying to come up with an economically viable solution to the copper impregnated PTFE seal here

Question about OM61X piston vacuum pump parts

because that's the only really tricky bit as far as I can make out. The rest of the parts could be either reused - instant gasket-ed - or bought as parts for the earlier pumps (non return valves)

If anyone can help please do!

__________________
1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

Interesting!!!!!

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Did you just pass my 740 at 200 kmh in a 300SD?????

1978 300SD 'Phil' - 1,315,853 Miles And Counting - 1, 317,885 as of 12/27/2012 - 1,333,000 as of 05/10/2013, 1,337,850 as of July 15, 2013, 1,339,000 as of August 13, 2013



100,000 miles since June 2005 Overhaul - Sold January 25th, 2014 After 1,344,246 Miles & 20 Years of Ownership

Stretch,

What would I need to 'freshen' a high mileage vacuum pump?????

__________________
Did you just pass my 740 at 200 kmh in a 300SD?????

1978 300SD 'Phil' - 1,315,853 Miles And Counting - 1, 317,885 as of 12/27/2012 - 1,333,000 as of 05/10/2013, 1,337,850 as of July 15, 2013, 1,339,000 as of August 13, 2013



100,000 miles since June 2005 Overhaul - Sold January 25th, 2014 After 1,344,246 Miles & 20 Years of Ownership

Not much if you are lucky.

I'm about 80% of the way through a little DIY write up that's gone a bit ape **** as I've added in much more information than is necessary for just a rebuild - I have the answer to the whole does the piston park or not question - all good fun for a really really long winter this year; nothing worse than being stuck indoors with nothing to do...

I should have it done by the end of this weekend.

__________________
1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

Regarding Bearings.

I used Medway brand 626 bearings from here. These have 6 balls, with a metal cage.

Bearings 603 629 Open Stainless | eBay

This is for the earlier style diaphragm vacuum pump.

Been 6 months now with no problems.

Whilst I had the vacuum pump open I cleaned the valves, but left the original diaphragm, as it looked to be better quality than the replacement I had.

Here is a link to Medway. After reading about them making parts for transmissions etc. I felt confident in using these bearings.

Medway Bearings | medwaybearings.co.uk


The original bearings still looked ok. The plastic cage holding the balls in place was intact. But this upgrade gives me peace of mind.

Thanks for replies. I had read the post Stretch had listed. I was just a little leery yet...

The op is a good read.


Picked up some skf '8' ball 626 bearings. $14 each. Will try to list part numbers here soon.

__________________
Dave

1985 190D 2.2 auto--gone
1975 240D 4-speed--storage
1985 500SEL--daily driver
1985 300TD--bad rust, soon to part out...
1982 300SD--waiting on engine from RD
1984 190E--storage
1996 Dodge 2500 Cummins--daily driver