seal for fuel fastenings

Non-engine, eg: aerodynamics, gearboxes, brakes, suspension
Post Reply
smckeown
Posts: 120
Joined: December 9th, 2006, 4:57 pm
Location: West Sussex,UK
Contact:

seal for fuel fastenings

Post by smckeown »

I'm having a problem with my fabricated fuel rail. When screwing the pressure regulator into the end of the fuel rail, even with copper washers it's so far impossible to make a good seal, in fact it pours out. I have been able to screw a push on fitting into the same pressure regulator, and after some serious torque I managed to get it to seal.

Are there any sealants that will help make a better seal ? I understand I'll use some threadlock on screw-on fuel seals to ensure they don't work loose, but is there anything else that will have make a better seal without so much torque there's risk of stripping the threads ?

Here's a picture of the regulator, as you can see the regulator has all female fixings, and you can screw male push on ends or male screw on male ends
3 way pressure regulator
3 way pressure regulator
pressure3way.JPG (16.85 KiB) Viewed 8119 times
thank you
Sean
205 8v Track car
smckeown
Posts: 120
Joined: December 9th, 2006, 4:57 pm
Location: West Sussex,UK
Contact:

Re: seal for fuel fastenings

Post by smckeown »

I have some Hylomar Universal Blue sealant , so it could try that
205 8v Track car
Rich Ellingham
Posts: 118
Joined: June 23rd, 2006, 6:54 am
Location: Glasgow, UK
Contact:

Re: seal for fuel fastenings

Post by Rich Ellingham »

Ok so I had to go back to your 'readers car' post to see how you're doing this. In the back edge of the hex flats of the regulator should be O rings. If the regulator housing doesn't have a continuous 37 degree AN seat for the male fitting to sit against it must have orings on it otherwise it will always leak through the threads - the seat is what seals JIC AN fittings. Fuel lab regulators come with the orings for this reason. I had to blank off a fitting but the aeroquip -6 blanking plug did not have enough shoulder or head size to seal the o ring so I had to tap a washer to seal it which worked. If you do have a continuous seat in the housing then addition of a conical washer may help I believe EARLS sell them.

Rich
book 38
Yugo_Turbo

Re: seal for fuel fastenings

Post by Yugo_Turbo »

Teflon tape maybe?
smckeown
Posts: 120
Joined: December 9th, 2006, 4:57 pm
Location: West Sussex,UK
Contact:

Re: seal for fuel fastenings

Post by smckeown »

yes someone else has recommended PTFE tape.
205 8v Track car
Brooky

Re: seal for fuel fastenings

Post by Brooky »

I wouldnt use PTFE tape on these type of fittings, at work we never use tape on small bore pipe work.

Try using a paste, like they use with nitrous systems.
Guy Croft
Site Admin
Posts: 5039
Joined: June 18th, 2006, 9:31 am
Location: Bedford, UK
Contact:

Re: seal for fuel fastenings

Post by Guy Croft »

Fittings as shown in your photo seal should 100% on the cones, male and female. They never leak - if the cones and threads are properly formed and matching. This is what makes Aeroquip and Goodridge fitings such popular choices.

Attempts to seal fuel lines any other way are very risky. I mean, don't do it. Why? Because they can spring a leak and cause a fire. Leaking fuel injection systems are incredibly dangerous because of the delivery pressure.

GC
Yugo_Turbo

Re: seal for fuel fastenings

Post by Yugo_Turbo »

Brooky wrote:I wouldnt use PTFE tape on these type of fittings, at work we never use tape on small bore pipe work.

Try using a paste, like they use with nitrous systems.
Interesting...what kind of paste is it, what base?
I taught teflon tape would do the job, its frequently used on water lines in houses which are under pretty high pressure but I was wrong as I see :)
cantfindausername
Posts: 306
Joined: July 19th, 2006, 6:07 pm
Location: Crawley, West Sussex
Contact:

Re: seal for fuel fastenings

Post by cantfindausername »

Agreed that they should seal on the mating surface. That said tho, they're only as good as the machining job. I have in the past had bad fittings that wouldn't seal. I changed them out to replacements (of the same sort) and it fixed my problem. Check the mating surfaces are free from scores and other marks, debrie etc.
Guy Croft
Site Admin
Posts: 5039
Joined: June 18th, 2006, 9:31 am
Location: Bedford, UK
Contact:

Re: seal for fuel fastenings

Post by Guy Croft »

Worth noting that you must not connect alloy fuel unions to steel ones. This may be your problem. If you have to join, use braided hose with different fittings each end.

GC
Rich Ellingham
Posts: 118
Joined: June 23rd, 2006, 6:54 am
Location: Glasgow, UK
Contact:

Re: seal for fuel fastenings

Post by Rich Ellingham »

http://www.holley.com/169101ERL.asp assuming

Its is documented by many autohrs including Guy, do not use any sealing tape or paste on AN fuel system fittings.
book 38
Post Reply

Who is online

Users browsing this forum: No registered users and 46 guests