2006 XC70 Evap pump strip down

[scot850]

I am in the process of clearing my garage of hoarded old parts and junk, and came across the Evap. pump I did a write up on how to replace last year. I was about to throw it out, but noticed that it was possible to open the casing, and having recently 'repaired' a headlamp motor by servicing the unit, I thought I'd have a look at how this worked and what might cause them to fail.

Again, I can't promise this will fix a unit as I have no intention of trying it out by removing the new unit but thought others may be interested if you want to try to save money or interested how it works.

Opened Emissions pump and major parts

Close up of motor showing 2 T8 screws and pump parts

Firstly I cleaned the majority of the dirt off the unit as it had picked up a load of dirt being placed above the rear axle. It was fiddly to open as it has 6 latches that have to be opened simultaneously.
I found by releasing 3 at one end it allowed then to open enough to not snap back, and then tackle the other 3. It can be done, but be patient!

By carefully removing the 2 spade connectors from the pump motor contacts, I was able to carefully remove the motor without damaging the 2 white wires that run into the pump assembly.

Remove the 3 T10 screws that hold the pump assembly together, and carefully remove each part and place on a clean (un-like I did) surface in order. Take note that you can only fit the parts in one way, as there is a rounded indent on the sides of the parts that need to align during re-assembly. I also used a marker to identify where 2 parts fitted together when dis-assembling as my memory is poor. Also not the last piece you remove has a shaped cut out on the underside that holds the connector with the 2 wires running to it.

This was as far as I planned to go, until I realised the motor could be removed from the base-plate by un-doing 2 T8 retaining screws. Took a while to find a T8 bit in all my stuff!

Then realising the motor was similar to the wiper motor, I opened it up carefully to check it out. It is a cheaper version of the wiper motor (in my opinion) as it does not use copped commutators or carbon brushes. Perhaps the reason the pump stops working is because the commutator or 3 fingered brushes oxidise over time and become intermittent? Don't know for sure.

Motor parts after strip down.

Motor part number

Cleaned the internals with contact cleaner and the brushes with a small paint brush and re-assembled. I found the easiest was to do that (as with the wiper motor) was to install the winding shaft and brushes together first, and then carefully inserting the 2 parts together into the motor case. This prevents the brushes being damaged.

I used the wiper re-build info you can find on this thread to re-build the motor:

https://www.matthewsvolvosite.com/forums ... =1&t=68495

Re-tested the motor using a battery charger on 2A setting, and expected the same load whine as per the wiper motor, but it ran very quietly. At first I thought it wasn't running.

Pump rotor assembly

This picture shows the rotor and seals for the vacuum pump potion of the unit. The 4 'seals' are the 4 rectangles and they fit in the 4 slots in the rotor you can see.

Having cleaned the motor and refitted it to the baseplate, I reassembled the pump body. If I were doing this for real, I would carefully clean the mating surfaces of the pump and plates with rubbing alcohol first to ensure they were clean.

Rebuild is the reverse of the strip down from here.

Reassembled pump and motor assembly

Another view of reassembled motor

In this view you can see one of the 2 tabs that need to be carefully prised up to separate the motor casing.

Pump motor windings?

Not sure what these windings do, but didn't try to remove (couldn't see a point) as there are 2 flimsy plastic retaining clips that look like they would break if you look at them too hard!

Connector pins and matching holes in cover

Final picture showing the plug connector pins to the unit and if you look carefully in the background, you can see the holes in the cover they must pass through. Be careful aligning these before re-fitting the cover.

Not sure if this is of any help other than being an interesting exercise on a cold day in the garage!

Input, opinion welcome!

Neil.