'99 Fbody fuel pump asembly
Thread Starter
TECH Apprentice
Joined: May 2006
Posts: 360
Likes: 1
From: Kansas City metro area
'99 Fbody fuel pump asembly I am getting ready to modify a stock '99 Fbody fuel pump assembly to fit in a modified stock tank for my Chevy II. The assembly has 3 hose connections and some things that I am not sure about. I am going to have to shorten the assembly to fit in the shorter tank which I think is possible. But:
1. The center hose connection has a blue valve assembly on the tank side. I looks likw either a one-way valve or pressure valve. What is it for?
2. One connection obviously goes to the pump. What kind of tubing can be used in place of what is there? It has to be shortened.
3. I am curious if the other connection is for the return line and the pressure regulator. It is the black assembly on the bottom side of the assembly.
4. There is a small hose that goes from the pump to the bottom of the cup to some sort of valve. What is it?
I want to keep the cup and pump assembly so there is a sump to pick up fuel from. I would consider an external fuel filer/regulator. Any help is appreciated.
1. The center hose connection has a blue valve assembly on the tank side. I looks likw either a one-way valve or pressure valve. What is it for?
2. One connection obviously goes to the pump. What kind of tubing can be used in place of what is there? It has to be shortened.
3. I am curious if the other connection is for the return line and the pressure regulator. It is the black assembly on the bottom side of the assembly.
4. There is a small hose that goes from the pump to the bottom of the cup to some sort of valve. What is it?
I want to keep the cup and pump assembly so there is a sump to pick up fuel from. I would consider an external fuel filer/regulator. Any help is appreciated.
Joined: Sep 2004
Posts: 3,148
Likes: 12
From: Downers Grove, IL
1.The center outlet is for the EVAP vent line.
2. I would try to keep the factory flex hose there, but if it is too long you could use high pressure fuel injection hose from the autoparts store. Just make sure you use the high pressure EFI hose clamps and that the hose does not get kinked.
3. Yep its the return/regulator. Just put a T in the fuel line and then run this to one side, the output to the other side of the T and then the last side of the T goes to the fuel rail.
4. The small hose that goes to the bottom of the cup is for the venturi system. It uses pressure from the pump to suck fuel into the cup that surrounds the pump. That way you don`t have to have baffels in the tank. The pump stays submerged because the venturi system keeps the cup filled.
2. I would try to keep the factory flex hose there, but if it is too long you could use high pressure fuel injection hose from the autoparts store. Just make sure you use the high pressure EFI hose clamps and that the hose does not get kinked.
3. Yep its the return/regulator. Just put a T in the fuel line and then run this to one side, the output to the other side of the T and then the last side of the T goes to the fuel rail.
4. The small hose that goes to the bottom of the cup is for the venturi system. It uses pressure from the pump to suck fuel into the cup that surrounds the pump. That way you don`t have to have baffels in the tank. The pump stays submerged because the venturi system keeps the cup filled.
Thread Starter
TECH Apprentice
Joined: May 2006
Posts: 360
Likes: 1
From: Kansas City metro area
I have a fear of something like that happening but with advice I get hear at least it won't be because I didn't know how to do it. If the in-tank regulator is bad I will just put an external fuel filter/regulator. If anthing is easy I get nervous anyway. 
TECH Regular
Joined: May 2005
Posts: 406
Likes: 0
From: Bay Area, CA
I used the setup and installed it in my '73's tank. I cut the entire top half off and shortened the bucket to get it to even fit in my tank. I replaced the flex hose with fuel injection hose and installed one of the springs from the housing assembly intop the hose to prevent it from kinking as it actually would kink when installed in my shallow tank coming off the top. I even had to remove the little rubber boots off the bottom of the assembly for clearance. I then sent the output hose to a modified 3rd gen sending unit/fuel pump assembly and then off to a C5 filter/regulator and ran the return line back into the bucket. Works like a charm.
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Ya I too used a vette filter/reg in the end. I guess in this case it cant hurt if you dont mind ponying up the extra coin it only opens when pressure exceeds 58psi so consider a safeguard against your stocker ever letting go 
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