P38A EAS Compressor Repair Time

My spare compressor was making loads of noise when running. Removed the head & piston, but motor was still noisy. Found the rear bearing was loose in the housing, allowing the armature to wobble around & wearing the contacts somewhat.

Got another spare from pump with broken magnets, so thought it's time to make a good pump from the bits. The circuit boards in both pumps were de-riveted & sorted quite a while back when I replaced the thermal sensors.

Before:


Clamped the bearing cage in place with 17mm socket & g-clamp.



Gently peened over the aluminium bearing housing with flat punch. Here's the result:



Motor re-assembled with usual challenges getting the small ring to hold the brushes in place. Now it runs quietly.

Old piston & seal only producing about 90 PSI, so ordered new piston seal & barrel kit from X8R to fit later in the week.

I tried buying one of those bearings from a bearing supply house and they told me they are a custom size so if you don't have a parts pump with good bearing you may be out of luck trying to do a rebuild.

Gord Wedman said:

I tried buying one of those bearings from a bearing supply house and they told me they are a custom size so if you don't have a parts pump with good bearing you may be out of luck trying to do a rebuild.

Click to expand...

Tried Wych bearings? They've come up trumps for me in the past.

Gord Wedman said:

I tried buying one of those bearings from a bearing supply house and they told me they are a custom size so if you don't have a parts pump with good bearing you may be out of luck trying to do a rebuild.

Click to expand...

You can buy the phosphor bronze and get them made up.
If they are self aligning type, you can buy blanks and machine the bore to suit.

In both pumps the bearing was a good fit on the armature shaft, but just the retaining clip was loose allowing the bearing to move. Re-seating it sorted that.

Unfortunately only one pump is repairable, because the other has broken magnets from when the housing rolled of the bench a while back !!

Wazzajnr said:

You can buy the phosphor bronze and get them made up.
If they are self aligning type, you can buy blanks and machine the bore to suit.

Click to expand...

This was actually a caged ball bearing. I was trying to take things apart and ended up pounding on the armature shaft and ruining the bearing. Luckily I have several spare pumps and valve blocks.