The Classic Machinery Network

lonesomegeorge wrote:Well, I pulled the top off of that tower and it had 4 sock filters, and they seemed to get fuel through them easily. I filled the housing up with fuel before putting the top back in. hooked up a preassure guage, but get no preassure . and the tower is almost empty of fuel. Is that small housing that the fuel line comes into below the lift pump supposed to be a check valve? it only had a spring and a lineup button inside to keep the spring straight. Is there another part that is missing? I don't know how it could be a checkvalve the way it is. any ideas?

terry

Hi,
It sounds as though you've found your problem.
There should be a top hat shaped plunger with a rubber looking seat on it at the end of the spring. It is the fuel pressure releif valve without which you cannot make fuel pressure so the engine will not start.
In service we found we had to replace the plunger and spring from time to time if fuel pressure dropped off, most Cats are simmilar.
You should have no problem getting replacements and I would use a proper Cat guage if possible.
A kit is available to change the cotton reel /sock type filters to a paper element if you wish, I have changed a couple rcently.
Fred

here we go again, the check valve before the transfer pump wasn't lined up right, straightened that out put it back together. now the filter housing fills up with fuel, but no preassure. Kind of points to the check valve again. how much preassure should I be looking for?

terry

Check fuel transfer pump, it the fuel stack is draining off, may have a sticking check valve spring within the transfer pump., if stuck open, you will have very low pressure or none, as fuel will not get to filter housing and will just go back to fuel tank. Fill your fuel tank to at least over half full.
Martyn
My D4 started ok when I first had it and the fillters were shagged. Photos of filters on CMN. D4 restoration

That is a cracking tip there

thanks guys for all your help. it appears that there is a bunch of silicone gasket crap flotting around in there. I can blow everything backwards and i'll get a good flow, for awhike, and then it will plug up again. its the fuel feed from the transfer tube, and the passage way from the filters to the fuel injector pump.
does anyone know the part# for the filtrs. it is the 4 long round filters.

thanks, terry

7B8264 filters 4

On my 1953 D-4 cat ,is there any reason why I couldn't install a fuel return line. it would sure make it easier to purge the system and bleed out the air. do the injectors need a little back pressure? I was thinking about a needle valve in a 1/4" line. any thoughts?

terry