403 Water Pump

peterg · #1 (**permalink**) 09-01-19, 08:59 PM

Are these easy to take off and service? Ran the engine up and noticed a small stream of coolant running down the water pipe from under the pump/ thermostat

Geoff Dowdle · #2 (**permalink**) 09-01-19, 10:30 PM

Peter,
It sounds like the seal in your pump is defective.
The pump will need a rebuild or if badly corroded, it will be best to replace it .
You need a puller and press to rebuild it .

The easy part of the process is the removal and refitting of the pump

Geoff

HughMiller · #3 (**permalink**) 10-01-19, 10:45 AM

I know that INRacing in Nottingham (Engineering and Machining - INRacing) will recondition Bristol water pumps, though it's quite expensive. I believe they can also supply new impellers, if you want to be really thorough.
They charged me £250 + VAT.

innellan House · #4 (**permalink**) 11-01-19, 05:33 AM

peter,
your pump may be rebuilt using a new carbon-ceramic seal. This involves machining a new seat for the carrier of the carbon disc. The ceramic part is mounted on the impeller (see photos). So the important point is that there should not be significant corrosion in the bore which prevents machining a new seat. You cannot ascertain this until you take the pump apart and remove the old seal. BOCA spares I think provides an exchange service or can supply a new pump ready for you to use if you have no machining facility. Ask Julian Caples.
sincerely,
vincent chai

Geoff Dowdle · #5 (**permalink**) 11-01-19, 10:23 AM

Vincent
You forgot to mention that BOCA Spares are only available to Full Members of BOCA .

Note
I don't use the ceramic seat and prefer the seal to run directly on the impellor.

Geoff

innellan House · #6 (**permalink**) 12-01-19, 09:40 AM

Geoff,
The carbon disc - cast iron (impeller) seal has stood the test of time. I must have been thinking of the BOCA bronze impeller which is used with the ceramic disc.
sincerely,
vincent

mjolner · #7 (**permalink**) 16-04-19, 08:29 AM

S P pumps Warrington almost while you
wait,2 hours, did a Bentley pump for me £110

peterg · #8 (**permalink**) 22-07-19, 02:06 PM

Finally got the pump off (well, my welder did!) and took it to a local 'reliable' engineer Water Pumps - Vintage, Veteran & Classic Water Pumps - UK
Cost £200 plus Vat but he had a lot of trouble getting the pully and impeller of. He said Bristol were very thorough!

The old bearing is hand pressure seized.

The offending top bolt was virtually seized into the block by corrosion. Now to refit with new ss bolts and plenty of anti corrosion fluid. A non standard part are studs in place of the two lower bolts with W/W nuts.