How to remove ABS motor bearing?

[MyWifesBoyfriend]

2004 Volvo V70 w/ 100k miles

Getting an intermittent fault code for "pump motor supply voltage faulty" (BCM-0070). It goes away after clearing it but eventually returns. Did some research and it seems that the most common cause is worn brushes inside the motor. Apparently they wear down from the self-test procedure after every start, which tracks considering the vehicle's age. The motor is simple to remove without touching any brake lines or hydraulics. Unfortunately there are no pick and pulls around me and local wreckers want $400+ for the motor, so I figured I would attempt to replace the brushes myself.

Problem is, how on earth do I pull this bearing with no clearance? I've seen posts where users were unable to remove the bearing with normal pullers, as well as other posts were users replaced the brushes with no mention of the bearing at all, suggesting it's no big deal. Is it possible to replace the brushes without removing the bearing?

And sample photos of said brushes. They appear to be 5x5x12mm brushes but I'm not sure of the material - copper carbon was recommended?

This car is a daily driver so I am trying to research as much as I can before I do anything to minimize downtime.

 

[MyWifesBoyfriend]

Also, for whatever it's worth, I've seen "12" stamped on the brushes in various photos I came across. Apparently this may indicate the metal to binder ratio and 50-75% copper content? Any insight is greatly appreciated.

 

[Arc]

You will need a bearing puller like this that wedges under the bearing to lift it.

https://m.media-amazon.com/images/I/81Ku9PntCoL._AC_UF894,1000_QL80_FMwebp_.jpg

 

[Exhaustgases]

Almost need a special stand to reach in close to the shaft, to support it close and then press it out of the bearing. Hopefully its not pressed too tight. And like the post above maybe that would work too.

 

[FowVay]

Because it may be nearly impossible to get a bearing puller underneath the bearing, you might need to remove the dust cover and insert a puller into the bearing groove. These pullers are called deep groove ball bearing pullers and they work by gripping the ball groove.

Twenty-five bucks for a cheapy Chinese model might work:

Insert it like this:

 

[Arc]

Because it may be nearly impossible to get a bearing puller underneath the bearing, you might need to remove the dust cover and insert a puller into the bearing groove. These pullers are called deep groove ball bearing pullers and they work by gripping the ball groove.

Twenty-five bucks for a cheapy Chinese model might work:

View attachment 320970

Insert it like this:

View attachment 320971

I've never seen one like that. Does it work?

 

[Arc]

Looking at those bottom pictures it appears as if it just lifts out of the can and is sealed by a rubber o-ring. If so you don't need to remove the bearing at all. Just pull it out and slap a set of new brushes in it.

 

[Astro14]

I've never replaced one of these - and most of my P2 Volvos are well over 200,000 miles. I would call Erie Vovo and see if they have an ABS module.

 

[Dave9]

Looking at those bottom pictures it appears as if it just lifts out of the can and is sealed by a rubber o-ring. If so you don't need to remove the bearing at all. Just pull it out and slap a set of new brushes in it.

This. Once you have the top cover off with the motor still captured in the bearing, use a puller to push the motor shaft out, or a hammer while supporting the back of the top cover. If the bearing is damaged in the process, replace the bearing.

 

[MyWifesBoyfriend]

Looking at those bottom pictures it appears as if it just lifts out of the can and is sealed by a rubber o-ring. If so you don't need to remove the bearing at all. Just pull it out and slap a set of new brushes in it.

This. Once you have the top cover off with the motor still captured in the bearing, use a puller to push the motor shaft out, or a hammer while supporting the back of the top cover. If the bearing is damaged in the process, replace the bearing.

Yes, the can pops right off, leaving behind the base plate and motor. I wasn't sure how you can replace the brushes with the commutator in place, but now that I think about it, the shaft should have enough play after the can comes off so that I can fit a puller on the bearing.

 

[MyWifesBoyfriend]

the shaft should have enough play after the can comes off so that I can fit a puller on the bearing.

Yeah okay, I think this is totally possible after watching this guy yank his motor apart and fiddle around with it (at 9:25):

 

[ctechbob]

Cut it off and press on a new one when done.

 

[BC1]

I bet the bearing will not be on there very tight. Put the bearing in your vise and tap the shaft with a brass drift. That should give clearance to get the bearing splitter under it. I had to do that changing an alternator bearing before.

 

[Oliveoil2]

The contact surface looks pretty scared and worn. New brushes for sure…but don’t expect them to last as long as the OEM ones did.

 

[MyWifesBoyfriend]

I've never replaced one of these - and most of my P2 Volvos are well over 200,000 miles. I would call Erie Vovo and see if they have an ABS module.

It's a pretty common issue (just search BCM-0070) but probably happens more often on city driven cars that see many drive cycles and thus, many self-tests cycles. Apparently Volvo changed the self-test procedure in the BCM sometime during 2007, and the later model year motors wear out significantly less. Curious if they used different brush materials too

 

[Dave9]

The contact surface looks pretty scared and worn. New brushes for sure…but don’t expect them to last as long as the OEM ones did.

Generally you'd take fine, then finer still, sandpaper and resurface the commutator, rotating the motor shaft so the sandpaper is making a parallel direction abrasion to the axis of rotation, like the brushes did.

 

[Dave9]

Yes, the can pops right off, leaving behind the base plate and motor. I wasn't sure how you can replace the brushes with the commutator in place, but now that I think about it, the shaft should have enough play after the can comes off so that I can fit a puller on the bearing.

I'm still not understanding why you feel that the bearing needs pulled? I might be looking at it cross-eyed but to me it looks like you don't want to disturb the bearing at all, simply to press the motor shaft out of it, with the bearing remaining in the base plate, or if the bearing comes out with the motor shaft, then that's that, but that it wouldn't be the intention to move the bearing at all from where it's seated in the base plate?

Is the motor shaft really tight in the bearing? Is it possible that the brushes just dug in a ridge in the commutator or there is a disc on the end of it, so all you really need is a couple of picks stuck in where the springs are behind the brushes to hold them back retracted while the motor shaft is pressed out of the bearing which stays in the base plate? - similar to what you're going to need to do anyway once you have new brushes installed and need clearance while putting the motor shaft back in?

 

[MyWifesBoyfriend]

Since I last posted, I gave the motor a couple taps and that mostly kept the "pump motor supply voltage faulty" intermittent code away. It came back once, but cleared itself on the next drive/self-test. With a spare motor on hand, I tore the original motor apart (well, it actually disassembled itself upon removal).

The original motor from 2004 was caked in carbon dust:

Here it is after a quick vacuum (note that the shaft is tilted to get a clear shot of the brushes):

For comparison, here is the spare 2012 motor with unknown mileage. It had some dust which I vacuumed off:

The 2004 motor brushes still seem to have some life left in them but it's possible that the shunt was preventing them from extending further? By comparison, the shunts on the 2012 motor seem to have more slack in them. It's also possible that the excess dust was causing issues and that the 2004 motor just needed a cleaning?

I swapped the 2012 motor on for now and may service the 2004 motor to keep as a spare. I'd like to disassemble it further to clean the commutator up and try to replace the brushes. The brushes appear to have a high copper content based on their appearance.

 

[JDenyer232]

I would take and blow all that carbon out with an air hose. I rebuild small brushed motors like these at work all the time. The ovens we use at work cook the bearings and when I replace them I also blow all the dust out and replace the brushes while I'm in there. McMaster Carr has a wide assortment of brushes, you just need to measure what you have so you can order the right size.

 

[CleanSump]

Electrical parts cleaner will get rid of that dirt without hurting anything.