Water Pump

[Stevev]

I have a question, I just got round to getting a replacement Jackshaft which arrived today.
My question is I now need to source a replacement water pump as mine is well and truly gone.
The old pump came out the block relatively easy and is a 12 vane one, what I need to know is are the 12 and 6 vane pumps identical to one another apart from the vanes fitted to the shaft. If so can I get either, a 12 or 6 vane replacement pump and just use my 12 vanes and fit to the shaft?

I know this might be a really silly question but I don't want to get the wrong one.

Cheers

Steve

[NickA]

imported post

Stevev wrote:

If so can I get either, a 12 or 6 vane replacement pump and just use my 12 vanes and fit to the shaft?

Yep, only one set of part no's for all the waterpump components. Vane's marked NSS so complete pumps have 2 different part no's.

[GDPR]

imported post

Don't forget if you decide to fit a 6 vane instead of a 12 vane the covers are different.

Russ

[robertt1948]

imported post

Hi Steve,

When I had to overhaul my pump I bought a repair kit which which included all the necessary parts. However, I through the new bearing away because I couldnt trust some cheapo bearing which it probably was. I am a great believer in using as many original Leyland parts as possible. I only used the seals and gaskets.

With regard to 6 and 12 vane impellors I believe that the 6 vane is more efficient thanthe 12. I suppose the 6 vane contains more water than the 12 ( less space occupied by the vane material ) so each revolution of the pump must shift more water.

If you stillhave the heads fitted you will have the old problem of getting the inlet manifold on again. Dont loosen off a head, as per the manual, or drill out the fixing holes or machine the manifold faces. Get the thinnest gaskets you can -there are different ones available - and make a tool to force the manifold into the V. I made such a tool which anyone can borrow and it works everytime. I've used it twice now. I'll photo it and post it on the Forum.

Robert

[GDPR]

imported post

Not had a problem getting the inlet manifold back on without loosening a head, but it does require some care to make sure the gaskets don't slip, and the thin gaskets do help - Paddocks do the thin ones, and I've used them myself with no problems.

Some owners have been known to stick the gaskets on to the heads with a very thin smear of wellseal or hylomar and bolt them down overnight with flat blocks of wood drilled to the manifold pattern - this allows them to make sure there isn't too much sealant blocking the head waterways, and helps to keep the gaskets in place while fitting the manifold.... this might be of help to you when you are fitting back up again.

Russ:dude:

[Stevev]

imported post

All,

Cheers for the info, my plan now is to find a known good 6 or 12 vane pump to recon. I will use my 12 vane impeller and the current pump housing which is for a 12 vane pump.
As I have know stripped my old pump down it actually looks pretty new so I guess its one of those doggy soft ones that was put in the engine approximately 7000 miles ago, I might be wrong but looking at the shaft its well gone no teeth left.
I hope to get the Jackshaft out in the next week or too, work permitting and then I should be ready to start the re assemble.
All sounds great but my other half always finds something more important that I have to do first which until now has hampered the repair .

Steve

[NickA]

imported post

Peter H of LDparts does decent quality waterpump parts, including RHP bearings

http://tinyurl.com/4bm9sn

[stagmuffin]

imported post

robertt1948 wrote:

Hi Steve,

When I had to overhaul my pump I bought a repair kit which which included all the necessary parts. However, I through the new bearing away because I couldnt trust some cheapo bearing which it probably was. I am a great believer in using as many original Leyland parts as possible. I only used the seals and gaskets.

With regard to 6 and 12 vane impellors I believe that the 6 vane is more efficient thanthe 12. I suppose the 6 vane contains more water than the 12 ( less space occupied by the vane material ) so each revolution of the pump must shift more water.

If you stillhave the heads fitted you will have the old problem of getting the inlet manifold on again. Dont loosen off a head, as per the manual, or drill out the fixing holes or machine the manifold faces. Get the thinnest gaskets you can -there are different ones available - and make a tool to force the manifold into the V. I made such a tool which anyone can borrow and it works everytime. I've used it twice now. I'll photo it and post it on the Forum.

Robert

robert i agree that bearing quality can be dubious and always use the best i can get.some seals are not up to the job either so buy from a reputable suplier if they are problematic this would show quickly if they sell a reasonable amount.then they would be able to rectify which they should have done by now.i have done four pumps on different vehicles in two years and all fine with parts from t.hart and paddocks.with regard to pump output 12 vane has been proven in tests to deliver more than 6 vane ( stag technical reprints from club mag) irun 12 and am very happy with performance. i to stick my gaskets on head first with welseal compound then fit manifold next day,never had any issues getting bolts to line up always been easy must be lucky i guess but i always heliciol heads with 2d 5/16 unc inserts that have not already been done.cheers steve.

[alan_thomas]

imported post

robertt1948 wrote:

Hi Steve,

When I had to overhaul my pump I bought a repair kit which which included all the necessary parts. However, I through the new bearing away because I couldnt trust some cheapo bearing which it probably was. I am a great believer in using as many original Leyland parts as possible. I only used the seals and gaskets.

With regard to 6 and 12 vane impellors I believe that the 6 vane is more efficient thanthe 12. I suppose the 6 vane contains more water than the 12 ( less space occupied by the vane material ) so each revolution of the pump must shift more water.

If you stillhave the heads fitted you will have the old problem of getting the inlet manifold on again. Dont loosen off a head, as per the manual, or drill out the fixing holes or machine the manifold faces. Get the thinnest gaskets you can -there are different ones available - and make a tool to force the manifold into the V. I made such a tool which anyone can borrow and it works everytime. I've used it twice now. I'll photo it and post it on the Forum.

Robert

Robert, It would seem that testing proves the opposite ie 12 vane is more efficient than 6 vane. The following was quotes in a recent thread -

I printed page 83 from SOC technical reprints which was attached to a forum post recently, sorry but I have lost track of which post!!

It states that 12 vane pump and 3 row rad will pump 86lites/min at 3000rpm engine speed. 12 vane with 4 row rad 92l/min. 6 vane with 3 row rad 64l/min.



Alan

[alan_thomas]

imported post

Steve,

I would certainly try my 'file test' on the water pump shaft before fitting your 'new' one in see this thread (my file test is a fair way down the thread.

- Alan

http://stagownersclub.mywowbb.com/forum1/2525.html

[GDPR]

imported post

With regard to 6 and 12 vane impellors I believe that the 6 vane is more efficient thanthe 12.

This debate is an old cherry - there is a body of opinion that quotes the 6 vane as the better pump.... if this is so then why did they move from 6 to 12 vane at the factory? Surely they wouldn't have advocated the fitment of an inferior or merely equal performing pump on a cooling system that was already well proven to be marginal? Also it would have been far cheaper to continue to produce 6 vanes than retool for 12 and have to manufacture new pump covers.....the 12 vane has to be a superior pumping device.

There is one thing however that seems relativelywidely accepted - the 6 vane places less strain on the jackshaft and Howard Vesey favours the 6 vane for that reason - I have a 6 vanein my '77 Mk2 engine but that was what was in there when I bought it and I believe it to be only just up to the job as the rest of the cooling system is in very good order - I will change my pump only to go over to Craig-Davies electric, which I now have all the components in hand to do - just need a couple of days without the wife needing me to do something else..........

Just my opinion

Russ

[alan_thomas]

imported post

kryten wrote:

With regard to 6 and 12 vane impellors I believe that the 6 vane is more efficient thanthe 12.

There is one thing however that seems relativelywidely accepted - the 6 vane places less strain on the jackshaft and Howard Vesey favours the 6 vane for that reason -
Just my opinion

Russ

Russ it stands to reason that if the 12 vane pump is pumping more water around as indicated in the tests then it is doing more work and hence will put more strain on the water pump drive. - Alan

[Stevev]

imported post

Alan,

Thats great info on the file test. I have just tried it on my damaged shaft and it seems to be a good one as I could not file a groove just make a shiny spot.
The shaft also has a grove for the small rubber 'O' ring seal and the 'splines' at the end of it so all in all I suspect the reason it failed is due to poor service.

Oh well I will keep a look out and try the file test on what ever I replace this one with, I will also use all the other suggestions in this thread to achieve what I hope will be a satisfactory recon water pump replacement.

Once again thanks for all your help.

Steve

[Sheepdip]

imported post

alan_thomas wrote:

kryten wrote:

There is one thing however that seems relativelywidely accepted - the 6 vane places less strain on the jackshaft and Howard Vesey favours the 6 vane for that reason -
Just my opinion

Russ

On that basis - is the auto more likely to be affected then as engine speeds are generally higher? I'd like to think this is the case as my auto failed with new parts, unfortunately tho the old and serviceable parts were also from an auto....