Fitting a water pump impeller?

Hi, I have purchased an impeller and thermostat. I am no mechanic but would like to have ago at doing the work myself,Is this wise and is the job a hard one?? I have looked at where they go and wonder if i have to take the two bottom pulleys off and the cam belt cover?

Thanks a bunch  :wink:

Gav
1983 gti

 the water pump is bolted to the block mate, there is an O ring between the mounting faces, you need to take your original pulley off the old water pump, its just bolted on, its quite a straightforward job just take your time and clean the mounting surface with a bit of emery paper or simmilar and make sure block surface is clean and dry before you fit the O ring to the pump housing recess and then bolt it up or you will get a leak! dont forget to fit in the stat!!!

fill with water/anti freeze, before you start it! and squeeze the top and bottom rad hoses, keep a watering can next to you to top up and check the level with the cap off whilst its running for a short while or untill reasonably warm, if its working correctly and circulating once the stat opens then you should see water spitting into the header bottle from the small return pipe from the rad, sometimes you can get an airlock in the system so have the heater blower valve on in the car and set to hot so the matrix is purged of air too, refit the cap once you happy the level is right ish and go for a little spin, if the fan isnt cutting in still then you need to check that sender, but hopefully it should be sorted, DONT take the rad cap off when its red hot though!!! let it cool and top up level if necessary, i dont put anti freeze in untill im happy i am happy theres no leaks!! waters free anti freeze is expensive! the Anti/water mix should be around 60/40 this time of year.

You make it sound so simple  :dontknow:  so I have to take the whole pump off? not just the impeller?

Its easier if you spend another tenner and get the whole pump, when you try and split the halfs most of the 10mm bolts will shear.

and removing the impeller from the shaft is not that straight forward.

Gav778 said

You make it sound so simple  :dontknow:  so I have to take the whole pump off? not just the impeller?

didnt know you could buy just the impeller part??????? a whole pump is only about ?30 with the gaskets seals


honest its not that bad a job, just take your time and make sure everthing is done up properly when you re fit, if you not confident get a mechanic or a mate to help you out when you do it

Its easier if you spend another tenner and get the whole pump, when you try and split the halfs most of the 10mm bolts will shear.

Yeah I think im gonna send the impeller back, your right the bolts did shear  :roll:

Cheerz Gav
1983 Gti

I pulled off my waterpump last week.  I've worked on a variety of repairs across cars.  This was my first Mk1 waterpump change.  

For those that have power steering and air conditioning, the adventure is quite irritating between the belts, the compressor being in the way, and just more stuff to take apart.    Once I was down to the pump, it was really easy.

Four bolts hold the pump on……I wouldn't bother with an impeller change only , change the whole pump assembly.


Step into the work confidently…..it can be done.

Remove the fan shroud for more space.  


For the pulley, use penetrating oil on the 3 bolts the night before and soak.  Then make sure the hex key is seated correctly before yanking on it.   Even better if you use a second hex key to hold the pulley while cranking on the other bolt.

If you have an oil cooler there will be more hoses.  Also a great time to replace if it too is leaking or doing something else undesirable.


Label everything - there will be fasteners scattered all over your floor.


You need to get cable operated hose clamp pliers.   You will give up on the job right at the beginning if you try to remove/install hose spring clamps without this essential tool.


Regarding the thermostat and bleeding air bubbles out of the system, I drilled a tiny hole in the thermostat edge.  Orient it towards the highest side of the pump  (front on 1.8L) so air bubbles can flow through it even when the thermostat is closed.


Sand any corroded flanges - heater hose pipes, oil cooler, as as previously mentioned the surface of the block where the pump mounts.

This is also a great time to change other hoses and plastic flanges (thermostat housing and cylinder head flange that goes to the heater).  These deform or even crack and cause leaks.

For me it was worth the effort to do it myself…..would have cost a lot more to have someone else do it.   Although I will admit that once in a while I thought about giving it to a shop  (like when I spilled oil out of the oil cooler, had to knife off the old hoses from the heater pipes, and when AC compressor just would not get the hell out of my way.

If you get stuck on the way in, jump on this forum and discuss it - lots of support available here to walk you through it.

never bothered with penatration oil on the pully i used an impact driver which took 30 seconds oh so easy with the right tools.

Hiya all   I have fitted my new water pump,It has solved the rev counter problem???? and all the hoses get hot and the fan is kicking in   ,but the little bleeder is still telling me she is to hot??? and when i went to turn the heaters off after putting it all back together and refilled the coolent, it was stuck? so i kinda forced it back and now the no 3 setting doesent work?? its one thing after another