Go Back   Ford Truck Enthusiasts Forums > Older, Classic & Antique Trucks > 1948 - 1956 F1, F100 & Larger F-Series Trucks
Sign in using an external account
Register Forgot Password?


1948 - 1956 F1, F100 & Larger F-Series Trucks Discuss the Fat Fendered and Classic Ford Trucks

Reply
 
 
 
 
LinkBack Thread Tools Search this Thread
  #1  
Old 08-16-2014, 09:05 PM
gzirnhelt gzirnhelt is offline
New User
 
Join Date: Jun 2013
Posts: 16
gzirnhelt is starting off with a positive reputation.
fuel pump won't pump

I am making good progress. The engine runs great but i am continually having fuel pump problems. I finally bought a new one from Macs. It worked for a couple weeks but now it won't suck fuel. It is definitely the pump - there is no suction. Everything looks good. Are these pumps really that bad?
Reply With Quote
  #2  
Old 08-16-2014, 09:26 PM
AXracer's Avatar
AXracer AXracer is offline
Post Fiend
 
Join Date: Oct 2004
Location: Durham NC
Posts: 14,503
AXracer is a splendid one to beholdAXracer is a splendid one to beholdAXracer is a splendid one to beholdAXracer is a splendid one to beholdAXracer is a splendid one to beholdAXracer is a splendid one to beholdAXracer is a splendid one to behold
Chuck Frank
Sounds like you have trash in your tank/fuel line that is getting under the one way valves in the pumps. Fuel pumps are rather simple design. Rocker arm moves diaphragm in and out pumping the fuel, two one way (usually disk) valves only allow gas to go from tank to carb. If it doesn't pump it must be either the rocker arm pivot pin fell out (check, they some times work themselves out, especially on rebuilt pumps) the arm or cam is worn/broke, or the diaphragm is ruptured, or a one way valve is stuck open (trash or broken spring) Since the pump is new and did work my money is on the open valve.
__________________
Passionate about autocross racing!

1956 F100 Panel "GRACIE"
2007 Solstice GXP racer, the "KRAZED KANARY"
Third place finish 2009 SCCA National Championships
Reply With Quote
  #3  
Old 08-17-2014, 03:12 PM
gzirnhelt gzirnhelt is offline
New User
 
Join Date: Jun 2013
Posts: 16
gzirnhelt is starting off with a positive reputation.
thank you - problem found

Your note got me thinking. You are right this pump is a simple device. I took it apart blew everything out. As i stroked the pump lever manually i could see it had great suction. I reassembled and as i was putting it back on the engine i noticed that it is possible for the push rod to be out of the pocket which operates the pump lever. I was careful to make sure it was retained in the pocket on the lever. Hooked everything up and it worked great. Then as i left it running in the driveway while i swept out the garage it killed and wouldn't restart. It looks like the pushrod worked its way out again. In watching the pushrod i notice that it has a bend in it and that it rotates as it strokes. I am guessing that is why it works its way out. I'll get a new pushrod unless someone notices this post and tells me that pushrod should have a slight bend in it. Thanks again for the quick reply. That was the trigger to make me look further.
Reply With Quote
  #4  
Old 08-17-2014, 04:30 PM
EffieTrucker's Avatar
EffieTrucker EffieTrucker is offline
Kentucky Chapter Member
 
Join Date: Jan 2011
Location: Eastern Kentucky
Posts: 1,652
EffieTrucker has a great reputation on FTE.EffieTrucker has a great reputation on FTE.EffieTrucker has a great reputation on FTE.EffieTrucker has a great reputation on FTE.EffieTrucker has a great reputation on FTE.EffieTrucker has a great reputation on FTE.
I assume this is your '48 w/Flathead V8. The fuel pump push rod should be straight.

You should also check the stamped steel clip on the end of the rocker arm in the pump. Sometimes they will work their way out of position but still be attached. If this happens they won't hold the push rod in place.

In the first picture it is correct, in the second it is not:
Attached Images
  
__________________
“The rat rod is a whole lot of fun, in theory, until someone forces you to actually drive it.” - David Freiburger, Hot Rod Magazine

Kentucky Chapter Member
Reply With Quote
  #5  
Old 08-17-2014, 08:07 PM
gzirnhelt gzirnhelt is offline
New User
 
Join Date: Jun 2013
Posts: 16
gzirnhelt is starting off with a positive reputation.
Good idea

Thanks very much for the pictures. There is no question my pushrod has a gentle curve in it, so I'll have to replace that but after looking at your pictures I do need to check that clip on the end of the arm - I think it might have been damaged by the eccentric action of the bent rod.
Reply With Quote
  #6  
Old 08-18-2014, 12:03 AM
AXracer's Avatar
AXracer AXracer is offline
Post Fiend
 
Join Date: Oct 2004
Location: Durham NC
Posts: 14,503
AXracer is a splendid one to beholdAXracer is a splendid one to beholdAXracer is a splendid one to beholdAXracer is a splendid one to beholdAXracer is a splendid one to beholdAXracer is a splendid one to beholdAXracer is a splendid one to behold
Chuck Frank
There are several fueling problem topics going, here is an illustration Number Dummy posted in one of the others: Click the image to open in full size.
Pin# 9378 sometimes backs out of one side of the housing due to worn bore and the arm ***** That can bend the pushrod and or allow it to fall out of the cup. Spring #9380 keeps the cup onto the pushrod by acting like a shock absorber. Parts #9352 are the one way valves.
__________________
Passionate about autocross racing!

1956 F100 Panel "GRACIE"
2007 Solstice GXP racer, the "KRAZED KANARY"
Third place finish 2009 SCCA National Championships
Reply With Quote
  #7  
Old 08-18-2014, 07:23 AM
gzirnhelt gzirnhelt is offline
New User
 
Join Date: Jun 2013
Posts: 16
gzirnhelt is starting off with a positive reputation.
That's why the pushrod is bent

This diagram and explanation is really helpful. The original pump - or at least the one that was on there when I took it apart - did not have the spring and it had the bent pushrod. Mind you it is not much of a bend - but it is definitely not flat. So I am assuming that this happened along the way - presumably we got the spring out of the engine when we tore it down and rebuilt it but it has been a while. That probably contributed to the pushrod problem. Then when I put the new pump on with the bad pushrod - it can work its way out of the clip on the end of the fuel pump arm. In addition I am pretty sure the pushrod is worn some making it even easier to come out of place. I ordered a new pushrod from Mac's and I am sure this will solve the problem.
Reply With Quote
Old 08-18-2014, 07:23 AM
 
 
 
Reply

Similar Threads
Thread Thread Starter Forum Replies Last Post
How to check if my fuel pump relay is bad? BRONC-OH 1997 - 2003 F150 2 11-21-2014 11:11 PM
Fuel Pump Question pcantin 1968-2013 Full Size Vans 20 05-11-2013 11:37 PM
E-350 v10 crank won't start ddfreet 1968-2013 Full Size Vans 0 02-02-2009 05:24 PM
No power to fuel pump str8racing 1987 - 1996 F150 & Larger F-Series Trucks 11 07-17-2007 10:56 PM
Fuel Pump? ChurchBuilder 1987 - 1996 F150 & Larger F-Series Trucks 2 11-26-2006 10:11 PM


Go Back   Ford Truck Enthusiasts Forums > Older, Classic & Antique Trucks > 1948 - 1956 F1, F100 & Larger F-Series Trucks

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On

Forum Jump


Participate In The Forums

Create new posts and participate in discussions. It's free!

Sign Up »





All times are GMT -5. The time now is 09:40 PM.


Powered by vBulletin® Version 3.8.7 AC1
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Advertising - Terms of Use - Privacy Statement - Jobs
This forum is owned and operated by Internet Brands, Inc., a Delaware corporation. It is not authorized or endorsed by the Ford Motor Company and is not affiliated with the Ford Motor Company or its related companies in any way. Ford® is a registered trademark of the Ford Motor Company.

vbulletin Admin Backup