123 Vacuum Pump rebuild kit - WTF

[steeleygreg]

Got a few Mercedes in my coral which are going to need the vacuum pumps rebuild. These are the piston type, not the early diaphragm type. Other than the bearings, where to find the kit with valves and the various O-rings. Is there some source or various sources to get these from or are we screwed and need to convert to electric vacuum pumps?

Greg

[Maximan1]

Afaik rebuild kits are not available or are very expensive if you can find them. Best bet is to find a good used unit or splurge for a factory refurbished one at $350 + core from Arizona.

[Diesel911]

Originally Posted by steeleygreg

Got a few Mercedes in my coral which are going to need the vacuum pumps rebuild. These are the piston type, not the early diaphragm type. Other than the bearings, where to find the kit with valves and the various O-rings. Is there some source or various sources to get these from or are we screwed and need to convert to electric vacuum pumps?

Greg

It is not the valve or the O-rings that are the issue it is the what I am going to call a nylon ring on the piston that is the issue and to a lesser extent the molded O-ring on the cover.

The disc valves may be the same disc valves that are non the diaphragm pumps. The diaphragm pump kits come with some diamond shaped rubber piece and 2 discs valves sold separately from the Diaphragm. So the valves are available.
More about everything here.
Question about OM61X piston vacuum pump parts

[jsp300D]

Buy a second hand diaphragm type and rebuild those

[Maximan1]

I just happened to be watching a engine swap on an Australian delivered Nissan patrol with the 4.2 diesel and noticed a possible retrofit solution. The Bosch alternator has a attached vacuum pump on the back of it. The alternator is available in CA warehouses (although it's a Australia delivered engine) from eBay for under $100, with the vacuum pump included. I do not know the output of the vacuum pump, but it is a potential workaround for a bad OM61x pump, with just a longer brake booster hose, different alternator plug, and possibly some modifications to the alternator bracket.

https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.com%2Fulk%2Fitm%2F233414182356

[75Sv1]

There is a vendor on EBay that rebuilds MB Vacuum pump. I did buy one. Its working good.

[strelnik]

Originally Posted by Maximan1

Afaik rebuild kits are not available or are very expensive if you can find them. Best bet is to find a good used unit or splurge for a factory refurbished one at $350 + core from Arizona.

Which begs the question: who refurbished the pumps and where did they get the parts?

[BillGrissom]

I bought a rebuild kit ~6 yrs ago off ebay for $105 as I recall. The critical part is the piston seal (aka "ring") which I vaguely recall is like an O-ring inside a teflon U-channel. You have to be very careful to not tear the teflon when stretching it slightly to slide on the piston. There is a similar kit on ebay now that I tagged, but ~$175. I think the disk check valves are identical with VW vacuum pumps. People ask $75 for the outlet fitting w/ check-valve and most are gone at the junkyards. You can find posts about replacing the roller bearing on the arm. Most use one w/ metal side shields to capture the balls. If that bearing fails, the arm can be cut thru to slide down into the timing chain (bad). I caught that in one of my cars my son had. It was making a rattling noise and had half cut thru the arm in just 100 miles of driving.

Thanks to Diesel911 for the link to the Nissan alternator w/ vac pump. Might be the solution to our problem. I'll see if there is room to fit one. I have a used electric vac pump from a VW diesel to try, but haven't bought a vacuum switch for it yet. Some say the duty cycle for our cars is too much for one, due to the constant leak for the transmission control.