TR4/4A AC Fuel Pump Priming Lever Stuck

[bammons]

I have another thread going here but I ran into a problem with the AC original fuel pump. On the advice of some I decided to replace the Moss replacement fuel pump with the original AC unit. I took the copy off. Cleaned the AC up and in the process of rebuilding it I noticed the priming lever would not move the cam lever or vice versa. Using some effort I could get it to move but I have to apply pressure to get it to go through it's movement range. So I squirted some brake cleaner in there and worked it and then some 3 in 1 oil without much effect. I have the cam lever out and the spring return on the priming lever out so neither of them is causing it. Anybody had this problem and if so how did you correct it? Bruce

 

[poolboy]

I think they are independent..I know they are on a pump for the TR6's

 

[bammons]

Even if they are independent, I can't smoothly operate the priming lever. It seems to hang up about mid way thru it's stroke. The replacement pump operates the priming lever when moved and vice versa. Both are supposed to operate the diaphram. Bruce

 

[charleyf]

Even if they are independent, I can't smoothly operate the priming lever. It seems to hang up about mid way thru it's stroke. The replacement pump operates the priming lever when moved and vice versa. Both are supposed to operate the diaphram. Bruce

I just went and tested an AC pump. What I got is----
The priming lever does NOT activate the cam lever.
The cam lever does NOT activate the priming lever.
The priming lever only goes what I believe is about 1/2 a stroke.
The cam lever is only moving about 1/4-3/8".
What I do get when I operate either lever is a sucking sound. Which I believe is good.
I suspect this is an older pump not recently rebuilt.
Charley

 

[bammons]

Ok my problem is the priming lever. On my non AC pump which I am wanting to replace with the original AC the lever goes to the top and the sides of the priming lever come into contact with the body and stops it. It should return downward where the priming lever hits the bottom stop. On my AC unit it tries to stop about 1/2 way on it's travel and can be pushed the rest of the way down with effort. I have soaked it and worked it repeatedly and it is a little less hard to push but not enough for the spring to overcome and push it all the way down. I could use it as is I guess and just not have a working prime lever. Or order a another new one to try. Bruce

 

[charleyf]

Ok my problem is the priming lever. On my non AC pump which I am wanting to replace with the original AC the lever goes to the top and the sides of the priming lever come into contact with the body and stops it. It should return downward where the priming lever hits the bottom stop. On my AC unit it tries to stop about 1/2 way on it's travel and can be pushed the rest of the way down with effort. I have soaked it and worked it repeatedly and it is a little less hard to push but not enough for the spring to overcome and push it all the way down. I could use it as is I guess and just not have a working prime lever. Or order a another new one to try. Bruce

Have you removed the diaphragm and looked inside to see if the AC unit acts the same without the diaphragm?
Charley

 

[bammons]

Charley - Yes it is completely apart even the cam lever is out. I don't understand what the issue is but It is inside and not accessible so I think I have to call uncle on this. So I will simply buy another pump and hope it is OK. Then I will have one new one, one that is one year old and one original AC that does not function properly. You know I have been on another thread about my issues and I am just bummed out as I don't even know if it is the fuel pump or whatever else it might be. I don't seem to have much option to get a professional to look at it but I may just park it for a while until I figure something out (it cannot be driven far now). Working on the car is fun to a point then it is not. I do appreciate your help and everybody else's. Bruce

 

[charleyf]

Bruce,
With the other new fuel pump, if you push on the cam arm do you get any sounds like it is working ? If so I would then check the very fine filter located above the sediment bowl. If that is clean then I think you would be okay to use that pump.
But now you need to move to the fuel line and make sure it is not obstructed or partially obstructed. I believe I suggested how to do that in the other thread.
Charley

 

[bammons]

The new (1 yr) pump has a plastic rimmed filter on the bowl. Upon removing it I found it was curled up and will not straighten out. I saw that a filter can be bought that works at TSC. That was not obstructing the gas flow though that I could tell. I did release the clamp in the engine compartment (below the pump) and got a strong flow of gas so I am not pursuing that any further back. I did put together the original AC pump and am mounting it today, whether the priming lever will work or not I will have to see. This is the only fuel related thing for me to try other that rebuild the carbs. Even though my distributor was rebuilt by Advanced Dist last year I am going to change out the points and condenser. I will take a test drive and after that I don't know. I will find some shop I supposed and leave it there and hope they know what they are doing. Bruce

 

[poolboy]

Yeah, the plastic filter screen should be replaced before it starts looking like this or worse.
If there is a good fuel filter upstream, you don't really need this one, but you can replace it with the original brass screen

 

[charleyf]

Bruce, Glad that you got a good flow from the fuel line. I agree that it should mostly alleviate concern about the tank and line.
Hoping your next test proves successful. Do not give up. Keep us informed.
Do you have a fuel filter prior to the carbs? If not a clear plastic one is a good idea. It let's you see the fuel. But be aware the filters I use never totally fill with fuel. Fuel only runs in the bottom 1/3.
Charley

 

[mctriumph]

Strain ahead of the pump. filter ahead of the carbs. It is a rule to be devoutly adhered to.
Unless you like trouble.....
Mad dog

 

[poolboy]

Because of the 2 one way valves in the TR6 fuel pump, it's a good idea to filter out the "fines" before they reach the fuel pump.

 

[bammons]

My filter on the glass bowl on the Moss pump looks like yours Poolboy only worse. I was by a Tractor Supply and bought one of their filter screens for tractor AC pumps . However my rebuilt AC pump does not pump so back to the Moss unit for now. Ordered a new one from BPNW. I was able to talk to a mechanic I know who is in transition of moving and was unavailable to me for a while and he is coming by to see if he can help. Yes I gave up, everything I have done has had no effect or made it worse. I will post what he finds. Thanks for everybody's advice, I have often relied on what you guys say with good results but this one has eluded us. Bruce

 

[charleyf]

My filter on the glass bowl on the Moss pump looks like yours Poolboy only worse. I was by a Tractor Supply and bought one of their filter screens for tractor AC pumps . However my rebuilt AC pump does not pump so back to the Moss unit for now. Ordered a new one from BPNW. I was able to talk to a mechanic I know who is in transition of moving and was unavailable to me for a while and he is coming by to see if he can help. Yes I gave up, everything I have done has had no effect or made it worse. I will post what he finds. Thanks for everybody's advice, I have often relied on what you guys say with good results but this one has eluded us. Bruce

Bruce,
We all love a good mystery. Please keep us informed when you find the solution.
Charley