Fuel Pump Non Return Valves 23mm

C

CRO757

Member
Hi,

I have found that my fuel pump (mechanical) is not working as it should. I have purchased a kit to put it right but I didn't realise there was a 19mm diameter NRV and a 23mm NRV. Just my look that I need the 23mm and I have the 19mm. is it possible to get the correct 23mm NRVs from anywhere.

Regards,

Ryan.
 
Hi Ryan,

The 19mm valves were much more common, and to make matters worse, there was never a distinction in part numbers to separate the two when purchasing kits.

I have never actually heard of valves being a problem, nor have I ever had the need to replace a valve or valves in over 300,000 Miles (500,000km) of driving my Rover. I am not saying that your valve isn't in need of replacment, just that it is unlikely.

The main diaphragm on the other hand do require replacement, if you replace that along with the pulsator diaphragm and the oil seal, you'll likely have the pump sorted. Do check though for distortion of the diaphragm cover. The tension of the screws in combination with the heat cycles distort the metal. Same applies to the surface that meets with the timing cover.

Ron.
 
Hi Ryan,

I have just had the same problem. You can get the pump overhaul kit for the 1" valve model from:

Peter Collins
Quality Rebuilds Ltd
85 Polo Prince Drive
RD1 Manurewa
Auckland 2576
New Zealand

email: peter@qualityrebuilds.com
website: http://www.qualityrebuilds.com
phone: +64 9 267 4700



Contact Peter and get a price. He's very good to deal with. He will also recondition your pump for you if required and it'll come back like new.

Good luck.


I think Ron's suggestion makes good sense. The valves are probably best left undisturbed.
 
Thank you.
The NRVs I have are cracked, however they possibly would have been okay for a bit longer .

I really didn't expect it would be so tricky to get these valves.

Regarding reconditioning in N.Z. I will contact him in the hope he knows someone here.

It's such a shame as this is a small part of a big problem.
Thanks again.
 
Yes the valves do go faulty and or wear, mine appears to leak back so that if the car sits unstarted for a few weeks you will wind a long time on the starter to recharge the carb.
 
ghce said:
Yes the valves do go faulty and or wear, mine appears to leak back so that if the car sits unstarted for a few weeks you will wind a long time on the starter to recharge the carb.
Click to expand...

Yes, I believe I may have this issue too, Graeme, although probably more pronounced. Whenever starting from cold, Occie takes a good few turns of the key to fire up but then runs quite happily. The fuel filter remains half-full when the car's been standing for a while though, so I'm unsure whether it is leak-back that's causing the issue.

I replaced the pump diaphragm about 7 years ago, but I remember at the time I didn't replace the valves as the kit came with the 3/4" ones whereas my pump has the 1" valves.

Without wishing to hijack Ryan's thread, does anyone know the reason for the two different valve sizes? Was it simply an AC redesign, or did Rover change the spec? Can a 1" valved pump be replaced with a 3/4" pump without issues?

Certainly the Parts Catalogue lists alternative pumps for early and late cars, which may coincide with the valve diameter change.

Stan
 
vaultsman said:
ghce said:
Yes the valves do go faulty and or wear, mine appears to leak back so that if the car sits unstarted for a few weeks you will wind a long time on the starter to recharge the carb.
Click to expand...

Yes, I believe I may have this issue too, Graeme, although probably more pronounced. Whenever starting from cold, Occie takes a good few turns of the key to fire up but then runs quite happily. The fuel filter remains half-full when the car's been standing for a while though, so I'm unsure whether it is leak-back that's causing the issue.
Click to expand...

I am not familiar with the V8 fuel pumps, but if they have the manual lever below like the 4 cyl ones, you could try to work them manually to prime the carbs before you start a cold engine and see if it makes any difference.

Fuel tends to evaporate from the carbs during summer, not really during winter, but i doubt that it can flow back from the float bowls.
My Austin has an electric fuel pump fitted, and I can hear it priming the carb for 2-3 seconds if the car hasn't been started for 2-3 days in really hot weather. However, during winter it only clicks once or twice, as the float bowl remains full during a similar or longer period.
 
Thanks, Demetris.

Yes, this would have been a good way of proving things, but unfortunately the V8 pumps don't have a priming facility.
 
Yes a manual primer would be really good, have one on my Austin Ten Four but it's valves must be in better condition as I never have to crank the starter motor to start it regardless of the time it has sat.

Graeme
 
The pump is an AC Delco item, or son of. They come in a large variety of valve sizes and lever/split linkage arrangements. I know my 1969 and 1971 engines would vapour lock under certain conditions no matter what you did. Altitude plus heat plus a days driving would do it every time. I think the bigger valves are to help alleviate this issue though I solved it on my 1976 car as it has the electric pump under the tank so vapour lock is pretty difficult to achieve. It isn't impossible though as the return line pumps hot fuel back to the tank so a hot day long drive and low tank could well still boil.
 
Hi,

I don't at all mind the 'hijack' thank you all for contributing to this.

First I would like to correct the valve size, I was told I needed 23mm but as pointed out here the outer diameter is 1 inch which is closer to 25mm which makes more sense.

Given that this restoration is a new project I fell at the first hurdle and I have decided to get an electrical pump. Although I favour the mechanical pumps on the whole, the electrical pump is simple to fit, if it fails it is is simple to replace and I can create a simple immobiliser system to it.

Ryan
 
The mechanical fuel pump that was manufactured in Australia by Goss for the 4.4 litre Leyland P76 V8 came with the small 19mm valves. I have used AC pumps with both size valves over the years in addition to the Goss pumps, and to be honest I cannot recall noticing any difference in terms of ease of starting, performance or limiting vapourisation.

Ron.
 
Has anyone replaced the NRV's? I've removed one to offer the new item but it looks like I might need to ream the recess out.
Any advice greatfully received.
 
I rebuilt my pump that had the large valves, but I could not get any large valves anywhere. I turned up some reducing inserts out of aluminium to go from large to small valves and pressed them in the body and staked them, then pressed the small valves into the inserts, it worked a charm..........................
then the bloody pump stopped pumping anyway probably due to a worn cam. It worked off the car in a test but there was not enough throw on the lever in situ.
I then threw in the towel and went to a Facet tucked up above the De Dion.
The inserts saved the day on the original pump though and did not take a lot of making.
 
Interesting. I bought a pump of eBay that has the smaller inserts (my own had the larger ones) but I can't fit the replacement NRV's from the kit, the base is too tight. I don't want to bash them in in case I damage them. Can't stand the ticking from the temporary facet square pump.
 
Hi
They are a tight fit,i used a thin wall socket and pressed them in a vice/then re stake.
just make a note of which way round valves are first .
Cheers,
Clive.
 
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