DIY: 1998 V70 S.A.S Pierburg Air Pump Rebuild (for $20)

enotslim · Post by **enotslim** » 13 May 2017, 20:54

Disconnecting the pump did not prevent the cel, just as you said. So I removed the pump (lots of debri in the water that drained out) and the plastic housing on the impeller side. Loosened the impeller by rotating a bit by hand (it was mildly "stuck" to start with but not bad, really). Now, if I grab the impeller stub with Vice Grips, the pump rotates pretty freely on the motor bearings. Most resistance seems to be the impeller rubbing against the remaining plastic housing. This is relieved by the weight of the motor and housing when swinging the whole thing by Vice Grips. I suspect the motor bearing itself does not need to be replaced. Any chance the motor will work after it dries out without further disassembly of the pump? I will try to pull the impeller but not sure that will be successful.

Any leads on a replacement motor? I read this thread saying the Graupner Speed 900 BB Torque equivalent is too large and haven't found anything more myself.

Post by **erikv11** » 13 May 2017, 22:44

Give it a shot, it's possible the motor can work. I doubt it but who knows.

If you can confirm the 850 and v70(98) have the same motor, I have an almost-new 850 pump (viewtopic.php?f=7&t=75710) that I should be pumping instead of sitting in my garage. Or you could swap over the V70 connector.

If you're going to put the SAS back together, remember you will need another SAS valve, its failure is why the pump filled with water.

enotslim · Post by **enotslim** » 14 May 2017, 09:54

erikv11: Thanks. I've been eyeing your 850 pump. Trying to keep original parts as much as possible just to see if I can ... . but may need to give up on that idea due to time. I guess swapping the connector would require splicing as I don't think compatible plugs exist on the 850 and V70(98) pumps.

Anyone recommend a good 12 V power source to bench test equipment? How does one do that effectively? Now that I've strayed into attempting this type of repair it seems that running cables from my car battery is "suboptimal" (as they say).

enotslim · Post by **enotslim** » 16 May 2017, 17:36

Is there an affordable way to pull the impeller that doesn't involve milling a split collar as described by the op? So far the impeller collar hasn't budged with WD-40, Lock-Ease, Vice-Grips and 5 mm drift. I can try PB-Blaster as well but it seems that a real puller may be needed. By my searching the Snap-On solution in this thread is well over $200. Obviously only for those doing many other jobs as well. It doesn't look like standard gear pullers will work unless they are very small. Any specific suggestion would be great. This type of work is new to me so any basic orientation would be very useful. Thanks.

enotslim · Post by **enotslim** » 03 Jun 2017, 09:31

After more than 2 days of PB-Blaster and using a bearing puller all I was able to do is damage the collar of the impeller. See photo. Is there any chance a machine shop (or someone else who actually knows what they are doing, which excludes me) can pull this or is it likely a lost cause?

enotslim · Post by **enotslim** » 14 Jun 2017, 21:22

Learned how to use a bearing puller and have everything in pieces - pump and motor. My main concern is whether the motor is salvageable. As 800artfreed posted previously, the bearing fell apart when the armature was removed with ball bearings flying into the magnets and both races are frozen in place. The small circle is what's left of the bearing that isn't frozen in the motor housing. I also have an electrical component that I broke or was already broken from the brush holder during removal (see image).

The rear bearing is probably OK as is but replacing the ball bearing might be tough. I'm also concerned that I actually need that broken component for the motor to run at all. I guess I can test this without replacing the bearings.

Has anyone identified a replacement motor?

800artfreed: If you're listening - was your mod successful to accommodate the longer Graupner Speed 900 BB Torque motor?

Thanks.

Post by **cn90** » 10 Nov 2019, 10:20

Now I wonder if there is a ghetto way of lubricating the small bearing to give the pump another year or 2.

Just a thought:

- Add engine oil the lower port near the impeller. You may need up to 1/2 quart.
- Just to soak the impeller area for a few hours.
- Then drain the oil and dispose of properly.

This should lubricate the bearing for a while...

Post by **abscate** » 10 Nov 2019, 11:27

Pulled a complete SAS off the 1998’parts car btw

Elpigo · Post by **Elpigo** » 21 Nov 2022, 08:50

Hi, I did everything mentionned in the 3 pics showing how to rebuild the motor and I'm now reputting everything back in place. I was wondering, is it really necessary to put the small metal plate over the bearing if this bearing is held in place between the small brass sleeve and the bearing. It's not easy to tap metal and install screws in this powerfull magnetic field, so I was wondering... If this plate is holding the bearing in place, there are few chances it moves (the bearing) if it is pushed in place by the small brass sleeve and the outside housing of the bearing.

Your thoughts

Thanks