Dakar 650GS Waterpump

Hi

About 14 months ago the club arranged a 650GS 'workshop day' at Atlantic. Mike and I went to see whether it is worth buying a BMW .  During the session the weeping waterpump were discussed. As I'm paranoid about all things technical I allways walk around the bike and 'kick the tyres' after a trip. That was when I noticed the drop of water on the exhaust under the waterpump.  A swipe with the finger confirmed the diagnosis. The botox girl is leaking at the small hole (wet after use), and that at 25000km.

Some research on the net confirmed that the waterpump must be treated as a 'consumable item'.  

All documentation warned about the oil pickup pipe and some other nasties that will be encountered during the repalacement.  It is about a 90minute job.

Ok, get the pump kit, pump cover seal and side cover gasket.

After inspection, contemplating, evaluation an refering to the information at hand I decided to use the following procedure.  (some read and some of my own invention)  

Drain the water, remove pump cover, remove side cover, replace pump, replace side cover, replace pump cover, refill water. Simple 

Ok that was the prolog.  At the end I think I found a 'fairly' easy way. (More difficult than taking it to the BMW workshop )

1. Drain Water (obviously) (Put this screw one side as it's got a brass washer to seal) Remove seat and left hand cover to release water cap.

2. Lay bike on side. It is WAY easier to work then.

Bike on side for easy access (After sidecover removed)

3.   Mark clutch arm position on CASING and gear lever on splines.  Remove clutch cable and gear lever. Check the play on the clutch lever before you feel resistance.

4.  Remove waterpump cover (no need to disconnect hoses)

5.  Remove 2 starter screws as well as side cover screws. It was easier to remove the whole footpeg to get to some of the screws. (one is behind the dreaded oil pickup pipe)

6.  Tap the cover with rubber mallet and wedge loose. (the gasket could make it stick.) the gasket could be saved if you watch it.

7.  Take the cover off.  BULLS!@#$TTTT. That oil pipe make it IMPOSSIBLE to get the cover off.

After reading what others did I realised none of them presented a (easy) workable solution.  The following worked without a problem.

8.  Undo the oil pickup pipe banjo fitting to the sump.  Have a small rag (cloth) to push into the banjo to stop the oil from seeping out.  I only did that much later - after a cup full of oil leaked out. You should not loose more than a spoon full if you plug it immidiately.

** the trick **

9.  Loosen the exhaust at the head and clamp to the back of the footrest. 

10.  Remove the screw at the top of the oil pipe where it is attached to the engine top. (this one was a bliksem as it is almost inaccessable)

11.  Pull the oil line out of the way and lift the side cover off.

** We found it impossible to get the oil pipe out of the way (except if we bend it).  It was a 30 second 'fight' once the exhaust was removed.

Closeup of cover removed

12. Tap the spring pin on the impellor side out and pull impellor off.

13. Pull gear and shaft out and 'unclip gear' (pin will fall out-keep pin)

14. Note oriantation (and depth) of seals and pry out.

OLD Pump kit

Note the score mark (left) on the shaft caused by the rubber water seal. This is where the water seeps past under pressure and is released via the weephole.   There is no lubrication at that point as the other seal (to keep oil from getting into the water) keeps the oil away (as it should)  You will notice that the second score mark from the left (oil seal) is still OK. it is actually only shining.

15.  Clean everything and tap seals back (note orientation and depth)  Keep them straight. (I use a socket as 'punch')

Cleaning and repairing

There are long stories about the type and amount of grase to put on the shaft at the water side to supposedly reduce the wear.  no comment from my side.

16.  Fit the impellor to the shaft with the new pin.

17.  Oil the gear side of the shaft and clip the gear over the pin.

18. Check/replace the side cover packing. Check cluch shaft splines and replace side cover. The oil pipe need to be fiddled a bit again. 

19. Tighten side cover, oil pipe to sump, oil pipe top bracket, starter motor. Replace exhaust (watch thin metal plate gasket), gear lever, footrest, clutch cable. (Move on splines to get same play as in step 3. Was I lucky with the splines on the clutch shaft? maybe as the play on the lever was the same.

20. Pick bike up and refill with fresh antifreezed water. There is a bleed screw on the right of the engine (near the sparkplug.) us a 11 socket to undo (two turns) and push a plastic pipe over.  Hook the open end of the pipe to the handelbar.  Squeeze the hoses to 'force' air out. No matter what I did I could not get 1Liter into the system.  There could have been 50 to 75ml left in the cavities of the motor.

Three hours later I rode out of the workshop.  With the exhaust trick it will next time defenetly be less than 90 minutes. 

Happy riding till the next one.  It could be anything from 25000 to 70000km

With respect to the type of antifreeze. People swear by anything from clean tap water to whatever.  I stuck to the 50% non Silicate stuff. (not the premix)

Happy Dakking

Adie