For me, there are two good reasons for fitting a Walbro. Firstly, Julian V at Overland fits them; which is reason enough. Secondly, because I can. OK in practical terms when you stand an 80 on its rear wheels, pointing skyward like some 4 wheel drive Scud missile, I think that the old pump struggles a bit to raise that precious fluid from the tank several meters below the engine bay. At times when I needed maximum fuelling, I have had several instances of stalling. Yep stalling an auto, which is a neat trick. When I used the hand throttle to idle up, it was OK but then with the extra revs on the clock, I could barely stop the thing with the brakes!
Following very helpful advice from JV, I secured a Walbro FRB 22 from APEusa.com
This is a marine quality (1000 hour salt water tested) diaphragm pump with a max pressure of 11 psi and max flow of 225 lt/hour. It doesn’t need massive pressure and flow; you are just trying to give the lift pump a helping hand. It only pumps on demand and is self priming. You can read all the spec on the website for yourself. It arrived in the UK after two days and stayed in Customs for a nice little rest until finally getting to me after I paid the additional £34 to UK Customs. The box arrived with nothing in it but the pump. There were no fittings at all. I did ask APE if they’d include some fittings to my needs but being American, probably didn’t understand me.
The threads on the pump are ¼ NPT. This is not the same as ¼ BSP although in its tapered form, it’s a pretty close match. The barbed end is 12 mm or ½” for the fuel hose. If you can get some ¼ NPT to ½ hose tail then fine. But with limited space, I wanted to go with 90-degree elbows, which I couldn’t find in NPT. My local fittings supplier got these for me.
They are ¼ BSPT in nylon. They really screw in a treat. For the technical nerds out there, the NPT is 18 tpi and BSP is 19 tpi, but the threads are also cut at a different angle. With the nylon fittings, there is a degree of conformity when you screw them in so they seem bob on.
I made a backing plate from some 40 mm strip. The idea is that if you mount the bobbins onto the pump it will droop and bounce around as you can only use two of them. With the plate, you can mount in three places and then bolt the pump tightly to the plate. Tah Dah! Proper tidy. Apparently, there is some vibration that can be transmitted into the cabin if you don’t use isolators.
I took the fuel line off at the first joint and fitted a stainless 100-micron filter just to stop any big lumps going through the pump. I have checked the tank and it’s actually spotless inside so it’s really a future precaution only.
This is also a handy way of joining the old and new pipe without having to take the original off the top of the tank. In a case of difficulty, the whole thing can be bypassed in minutes as all the original kit is still there. I fashioned a hose clip to keep things from jiggling.
Underneath there is a convenient flexible to metal joint. I split this and added in a piece of 12 mm hose to the inlet of the pump then another from the pump to the metal pipe. I ended up with two sorts of pipe. Plain rubber and cotton coated. The cotton coated is very flexible and I used this on the output side as you need to bend it a bit more to join back up to the metal pipe that goes to the fuel filter in the engine bay.
I agonised for some while about the location; it had to be easy to install, protected from bashing but accessible in case of problems in the field. There was a convenient hole near the bottom of the rail, which I used for the larger lower bobbin, and two new holes higher up. Obviously this was another great opportunity to get my riv-nutter out. Gotta love a riv-nut or two. The heat shield was interfering in terms of height, but as I have a straight through on now, it wasn’t needed. Quick mod later and the head-room wasn’t an issue any more. I needed to drop the prop to be able to get the drill in, but that didn’t take more than a few minutes.
As I am using the chassis as earth, I needed to put a small strap onto the bobbin mount as clearly the pump is insulated from the vehicle. I actually used two; one that came out of the pump loom and one directly to the casing after I had tapped out a convenient 6mm hole in the side of the body.
To power the pump I used the much under utilised auxiliary fuse box by the wing. The pump should only be energised when the key is turned. This meant using terminal IGN and a 5 amp fuse.
To join the supply to the pump I opted for a plain crimped bullet connector with silicone boots, white grease inside surrounded by some decent heat shrink tube. It’s not my idea of ideal for an external joint, but it’s pretty tight and weatherproofed. Out of the way, I think it will stay the course. It tucked conveniently inside the chassis rail.
I decided to put in a non-return valve by the main filter just as a precaution. It took no effort other than a snip and two clips (ooh, sounds familiar) and it just guards against drain back should there be any leaks in the system or whatever.
I disconnected the supply pipe and ran the pump to see what sort of delivery it had. All seems very good indeed. Pipe reconnected, all primed up, ready for a drive. Does it feel any different out on the road?
Well…..
Following very helpful advice from JV, I secured a Walbro FRB 22 from APEusa.com
This is a marine quality (1000 hour salt water tested) diaphragm pump with a max pressure of 11 psi and max flow of 225 lt/hour. It doesn’t need massive pressure and flow; you are just trying to give the lift pump a helping hand. It only pumps on demand and is self priming. You can read all the spec on the website for yourself. It arrived in the UK after two days and stayed in Customs for a nice little rest until finally getting to me after I paid the additional £34 to UK Customs. The box arrived with nothing in it but the pump. There were no fittings at all. I did ask APE if they’d include some fittings to my needs but being American, probably didn’t understand me.
The threads on the pump are ¼ NPT. This is not the same as ¼ BSP although in its tapered form, it’s a pretty close match. The barbed end is 12 mm or ½” for the fuel hose. If you can get some ¼ NPT to ½ hose tail then fine. But with limited space, I wanted to go with 90-degree elbows, which I couldn’t find in NPT. My local fittings supplier got these for me.
They are ¼ BSPT in nylon. They really screw in a treat. For the technical nerds out there, the NPT is 18 tpi and BSP is 19 tpi, but the threads are also cut at a different angle. With the nylon fittings, there is a degree of conformity when you screw them in so they seem bob on.
I made a backing plate from some 40 mm strip. The idea is that if you mount the bobbins onto the pump it will droop and bounce around as you can only use two of them. With the plate, you can mount in three places and then bolt the pump tightly to the plate. Tah Dah! Proper tidy. Apparently, there is some vibration that can be transmitted into the cabin if you don’t use isolators.
I took the fuel line off at the first joint and fitted a stainless 100-micron filter just to stop any big lumps going through the pump. I have checked the tank and it’s actually spotless inside so it’s really a future precaution only.
This is also a handy way of joining the old and new pipe without having to take the original off the top of the tank. In a case of difficulty, the whole thing can be bypassed in minutes as all the original kit is still there. I fashioned a hose clip to keep things from jiggling.
Underneath there is a convenient flexible to metal joint. I split this and added in a piece of 12 mm hose to the inlet of the pump then another from the pump to the metal pipe. I ended up with two sorts of pipe. Plain rubber and cotton coated. The cotton coated is very flexible and I used this on the output side as you need to bend it a bit more to join back up to the metal pipe that goes to the fuel filter in the engine bay.
I agonised for some while about the location; it had to be easy to install, protected from bashing but accessible in case of problems in the field. There was a convenient hole near the bottom of the rail, which I used for the larger lower bobbin, and two new holes higher up. Obviously this was another great opportunity to get my riv-nutter out. Gotta love a riv-nut or two. The heat shield was interfering in terms of height, but as I have a straight through on now, it wasn’t needed. Quick mod later and the head-room wasn’t an issue any more. I needed to drop the prop to be able to get the drill in, but that didn’t take more than a few minutes.
As I am using the chassis as earth, I needed to put a small strap onto the bobbin mount as clearly the pump is insulated from the vehicle. I actually used two; one that came out of the pump loom and one directly to the casing after I had tapped out a convenient 6mm hole in the side of the body.
To power the pump I used the much under utilised auxiliary fuse box by the wing. The pump should only be energised when the key is turned. This meant using terminal IGN and a 5 amp fuse.
To join the supply to the pump I opted for a plain crimped bullet connector with silicone boots, white grease inside surrounded by some decent heat shrink tube. It’s not my idea of ideal for an external joint, but it’s pretty tight and weatherproofed. Out of the way, I think it will stay the course. It tucked conveniently inside the chassis rail.
I decided to put in a non-return valve by the main filter just as a precaution. It took no effort other than a snip and two clips (ooh, sounds familiar) and it just guards against drain back should there be any leaks in the system or whatever.
I disconnected the supply pipe and ran the pump to see what sort of delivery it had. All seems very good indeed. Pipe reconnected, all primed up, ready for a drive. Does it feel any different out on the road?
Well…..
