S3 ex-MOD water pump

[rickv100]

I replaced the thermostat and the truck is still running hot. So my next item to replace is the water pump.

Which one is the correct one for the S3 ex-MOD 109? RN has about 4 to pick from.

Any suggestions/recommendations on which is the prefered one to get?

Rick

[Jim-ME]

I'd call them. They will be more than happy to help you sort it out.
Jim

[scatterling]

http://www.roversnorth.com/store/p-4751-water-pump-assm-ex-mod-series-iia-iii.aspx

[LR Max]

Before you do that, check your radiator. If it hasn't been gone through recently, that'll do more for cooling than a new water pump. Any radiator shop can do the work for cheap and it'll be good as new.

[albersj51]

A couple things I've read on here (no personal experience):

1. Look at the hoses, sometimes the inside comes apart blocking flow.

2. Is it overheating based on the gauge in the truck or by other means? I've heard of some where the gauge isn't working properly. Get a cooking thermometer and put the probe in the water/coolant via the rad cap (maybe the rad cap is a problem?) And confirm that your gauge is accurate.

You're probably right with the WP, but these are free to diagnose, so may be worth a look.

Good luck!

[rickv100]

Thanks for the advice. I can tell the radiator is overheating by just touching the top of the radiator tank.

Looking at the radiator it looks like it would not hurt to pull it and have it gone through while I am replacing the pump.

At this point the entire cooling system will have been gone through.

Has anyone flushed the block? How do you do it?

Rick

[disco2hse]

Thanks for the advice. I can tell the radiator is overheating by just touching the top of the radiator tank.

Looking at the radiator it looks like it would not hurt to pull it and have it gone through while I am replacing the pump.

At this point the entire cooling system will have been gone through.

Has anyone flushed the block? How do you do it?

Rick

Take it to a radiator specialist. It's a mucky job and the chemicals involved will turn you into the Hulk. But... if you want to do it yourself make certain you have a enough of a drain to handle the toxins and a hose with good pressure. Then Google instructions. I would suggest you use a pressure wash to clear any built up gunge.

[masonater]

Thanks for the advice. I can tell the radiator is overheating by just touching the top of the radiator tank.

Looking at the radiator it looks like it would not hurt to pull it and have it gone through while I am replacing the pump.

At this point the entire cooling system will have been gone through.

Has anyone flushed the block? How do you do it?

Rick

I tried one of those Prestone radiator flush kits from autozone or one of those places. It comes with all sorts of cleaners, treaters, flushers, ect. It also has a nice little hose adapter that you install inline with the heater hose, makes things pretty easy. But now that the 109 is all apart i took the radiator to a shop and they made it brand new for 50 bucks.

[jac04]

I can tell the radiator is overheating by just touching the top of the radiator tank.

Check it with a gauge or a thermometer. Even if everything is operating properly, there is no way you could hold your hand on the top tank. Usually around 140-150 F is the limit of how hot a surface you can stand to touch. If you have a t-stat around 180 F you won't be able to touch the tank for any length of time.

[JimCT]

water pump

If it is not leaking and not grinding because of bad bearings they rarely go bad.

[rickv100]

As far as I can tell there is no grinding noise coming from the water pump.

I think I am going to go with the radiator first and get that checked out.

Should I have a 8 blade or 4 blade fan if it is EX-MOD? I have a 4 blade fitted to my truck.

Rick

[jac04]

The water pump flange for the military 8-blade set up and the civvy 4-blade set up are different. If you have a single groove pulley and 4-blade fan, then you should have the civvy water pump.

[rickv100]

That is the odd thing. I have a single groove pulley and 4 blade fan but the water pump appears to have the vertical output like is pictured on the Rovers North Website.

I will take some pictures and post them online.

It appears that this truck was modified in its lifetime.

Rick

[73series88]

oh imagine that
aaron

[Les Parker]

Amount of bolts holding water pumps to front cover

Ref the difference :-

7 Hole Water pump = 24v MOD (Giant alternator on RH side of engine)
8 Hole Water pump = Series II
9 Hole Water pump = 12v Civvie and 12v G.S. MOD.

Hope this helps.