Home 
Home Search search Menu menu Not logged in - Login | Register

 Moderated by: Greg Fletcher
New Topic Reply Printer Friendly
Fuel leak  Rate Topic 
AuthorPost
 Posted: 08-29-2014 03:53 am
  PM Quote Reply
1st Post
davidpayne
Member
 

Joined: 02-08-2012
Location: Santa Cruz, California USA
Posts: 7
Status: 
Offline
I noticed a large puddle of fuel under my car. There was nothing leaking from the carb area, so I crawled under. Fuel was dripping from the oil pan. I drained at least a gallon or two of oil mixed with gas.

Background: a couple of days prior, the small hose at the top of the fuel tank broke nearly in half. I hadn't noticed that when I filled up. I had a spare hose from my parts car, so I replaced it. Could the hose fracture and then filling the tank have something to do with this?

Any clues would be appreciated.

Last edited on 08-29-2014 03:53 am by davidpayne

Back To Top PM Quote Reply  

 Posted: 08-29-2014 05:32 am
  PM Quote Reply
2nd Post
gmgiltd
Member
 

Joined: 07-10-2012
Location: Whitehills , United Kingdom
Posts: 168
Status: 
Offline
Hi David,
The 'small' hose on the UK spec GT anyway, is to prevent siphoning and should have a restrictor in it - it allows a small amount of fuel to be pumped directly back to the tank and ensures that the fuel line is not pressurised against the carb float valves with the ignition off.
Other possibilities are tank cap not venting allowing pressure to build up on a hot day, faulty float valves, car parked nose down hill (syphoning) or a combination of these. Hope this helps.
Gordon

Back To Top PM Quote Reply

 Posted: 08-29-2014 02:23 pm
  PM Quote Reply
3rd Post
Jim Ketcham
Member
 

Joined: 03-13-2005
Location: Salt Point, New York USA
Posts: 208
Status: 
Offline
In the US there is a small check valve hidden in the hose to prevent siphoning when the level in the tank is higher than the carbs. If you still have the old hose you can remove it and place it in the new hose. The parts manual shows this valve.

Back To Top PM Quote Reply  

 Posted: 08-29-2014 10:17 pm
  PM Quote Reply
4th Post
davidpayne
Member
 

Joined: 02-08-2012
Location: Santa Cruz, California USA
Posts: 7
Status: 
Offline
Update: A piece of rubber was discovered in the rear carb that was preventing the needle from seating. Cleared it and will do a rebuild, including changing the floats on both carbs.

Regarding the check valve, we did a little exploring and discovered the vent line that exits the bottom of the trunk area and the line that goes to the canister are both clogged, and likely have been for a long time. Rather than replace all of those lines, will I be okay just running a new hose from the top of the tank that simply daylights out the bottom of the trunk?

My assumption is that the previous hose, which I had not noticed was cracked open, was allowing the pressure in the tank to escape. When I replaced the cracked hose, this sealed the leak, but due to the clogged vent lines, pressure was able to build in the tank and this forced fuel to the carb which had it's needle held open by the small chunk of rubber.

Back To Top PM Quote Reply

Current time is 08:17 pm  
> Jensen Healey & Jensen GT Tech > Carburetors > Fuel leak Top




UltraBB 1.172 Copyright © 2007-2011 Data 1 Systems