Fixing air line leaks, advice?

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rasheed

rasheed

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Hello all. Did the soap bubble test today and found 3 slow leaks; connection to reservoir tank, connection to FR airbag and top connection to air-dryer. Did tug out the lines, clean, dab a bit of vaseline and push back in. Still getting bubbles. What's the correct way to fix this? Do the little locking collars need replacing? I've searched and only suggestion I find is to cut a bit off the end of the pipe and try again. Except can't really do that at the tank because there's no slack so the pipe would come up short.

Also noticed that there's a short sharp burst of air out the exhaust valve (on the valve block) whenever the compressor stops. Is this normal? Because then the compressor starts again. Then when it stops, another sharp burst of air and it starts again. It seems to be yo-yo-ing for some reason? :confused::confused:
 
rasheed said:
Hello all. Did the soap bubble test today and found 3 slow leaks; connection to reservoir tank, connection to FR airbag and top connection to air-dryer. Did tug out the lines, clean, dab a bit of vaseline and push back in. Still getting bubbles. What's the correct way to fix this? Do the little locking collars need replacing? I've searched and only suggestion I find is to cut a bit off the end of the pipe and try again. Except can't really do that at the tank because there's no slack so the pipe would come up short.

Also noticed that there's a short sharp burst of air out the exhaust valve (on the valve block) whenever the compressor stops. Is this normal? Because then the compressor starts again. Then when it stops, another sharp burst of air and it starts again. It seems to be yo-yo-ing for some reason? :confused::confused:
Click to expand...

Bursts of air = Normal, the reason it starts to pump again so soon is because it has leaks and the pressure drops and signals it to pressurise again, you need to fix it ASAP or the compressor will wear out in no time.
Vaselene? there is better lubricants available for rubber.
 
Now you mention it, they do say not to use it with condoms, don't they! :D

What you say about the compressor makes sense. Brings me back to: I need ideas on how to sort out those leaks.
 
You can buy couplers and pipe on Ebay so you can cut the pipe to the tank back and splice in a new piece. On the others you might need also to replace the "O" rings in the connectors.
 
Datatek said:
On the others you might need also to replace the "O" rings in the connectors.
Click to expand...

You mean air dryer and front airbag, right? I didn't see any O-rings at all. Where should they be? And does this apply to all 4 airbag connections too?
 
rasheed said:
You mean air dryer and front airbag, right? I didn't see any O-rings at all. Where should they be? And does this apply to all 4 airbag connections too?
Click to expand...

You push in a brass collar to release the pipe, behind the brass collar, inside the fitting, there are one or two "O" rings, they may need replacing, I believe they can be hooked out:eek:
 
Well that'd be a good reason for a leak then, if they're not there! Will look into it in the morning. Thanks Data!
 
The brass ferrule holding the air-line in place that Datateck speaks about, has 6 little fingers that are bevelled at the bottom on the inside and and are builtout on the outside at the bottom to lock them into the fitting, they are easy to remove but be careful when pulling them out as the fingers are very thin and easily snap off, rendering it useless. Pry them out parallel to fitting by using an eating iron (fork) suitably spread the middle prongs apart for the occasion to work them out of their fitting is what I found works OK.

There are 2 tiny O-rings, one on top of the other, below the ferrule, wifes crochet hook works well for me to dig them out.
 
As our friend from Oz said be care full. However you can buy these push connectors just about anywhere, they are not uneque to auto vehicles - any thing/place using air or liquids will have them. While you are at it for a quid buy a nylon air pipe cutter, it saves damaging the pipe and leaves the end nice and square. Be sure to push the pipe in all the way you should feel it click into position.
 
Thanks fellas. Much clearer now. I'm away for a couple of days and have left the car kneeling in prayer in the garage at home. Will pick all the bits up and have a go on Friday.
 
forgot to wrap this up. was the o-rings, at the bag, the dryer and the tank. after many false starts and whittling away of pipe i managed to fix those and a couple of days later the car was doing its camel impersonation and kneeling at the front again. this time it was the o-rings at the valve block outputs to the two front bags. seems by fixing one end the back-pressure affected the other end! so did those two and the car doesn't drop even 1/2 an inch overnight anymore. i've actually never had that and its almost disconcerting to see in the mornings. :) also compressor has quieted down so all is well.... hopefully for more than just the next 10 minutes! incidentally the ride is distinctly harsher on the jittery stuff but its also much better at speed (or what passes for speed in a P38..) and while cornering.
 
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rasheed said:
just to wrap this up, it was o-rings, at the bag, the dryer and the tank. fixed those and a day later the car was kneeling again. this time it was the o-rings at the valve block outputs to the two front bags. seems by fixing one end the back-pressure affected the other end! so did those two and the car doesn't drop even 1/2 an inch overnight anymore. i've actually never had that. and its almost disconcerting to see in the mornings. :) also compressor has quieted down so all is well.... probably for the next 10 minutes!
Click to expand...

Great to hear, be positive it's gonna be fine as long as you maintain it, it is a complex system, but if you keep onto the little thing when they first become obvious you'll get plenty of trouble free years from it. Took me a couple of rides home on the bump stops to learn this, but now that I maintain the system as it should be, I've had four trouble free years out of it.
 
rasheed said:
forgot to wrap this up. was the o-rings, at the bag, the dryer and the tank. after many false starts and whittling away of pipe i managed to fix those and a couple of days later the car was doing its camel impersonation and kneeling at the front again. this time it was the o-rings at the valve block outputs to the two front bags. seems by fixing one end the back-pressure affected the other end! so did those two and the car doesn't drop even 1/2 an inch overnight anymore. i've actually never had that and its almost disconcerting to see in the mornings. :) also compressor has quieted down so all is well.... hopefully for more than just the next 10 minutes! incidentally the ride is distinctly harsher on the jittery stuff but its also much better at speed (or what passes for speed in a P38..) and while cornering.
Click to expand...

Stupid question perhaps, but how exactly did you fix them? (ie did you replace the o rings and if so where did you get em?

Guy
 
kooky_guy said:
Stupid question perhaps, but how exactly did you fix them? (ie did you replace the o rings and if so where did you get em?

Guy
Click to expand...

Sometime it's as easy as extracting the leaky line, trimming a little from the end of the line, only a poofteenth though, putting a very fine smear of lube onto line and twisting it back into ferrule/collett thingy. rubber grease best, but nothing wrong with a little bit of soapy water
 
kooky_guy said:
Stupid question perhaps, but how exactly did you fix them? (ie did you replace the o rings and if so where did you get em?

Guy
Click to expand...

as ssmn says. however chances are quite high of scoring and scratching the pipe as you push it in and out, especially as it tend to harden with age. in my case i tried trimming several times but it kept leaking. so then i decided to fish out the o-rings (using a thin bit of stiff wire where i'd bent one end into a bit a of a hook) and found them flattened and deformed. tried generic o-rings from other places but none worked. eventually i pulled up the part number and got a set from a local parts guy who happened to have some from Britpart. FYI, there are 3 sizes, 8 mm for the lines to and from the dryer, 6mm for most other places and also 4mm (i only spotted one 4mm line coming out of the valve block, don't know where it goes or if there are more).
 
rasheed said:
as ssmn says. however chances are quite high of scoring and scratching the pipe as you push it in and out, especially as it tend to harden with age. in my case i tried trimming several times but it kept leaking. so then i decided to fish out the o-rings (using a thin bit of stiff wire where i'd bent one end into a bit a of a hook) and found them flattened and deformed. tried generic o-rings from other places but none worked. eventually i pulled up the part number and got a set from a local parts guy who happened to have some from Britpart. FYI, there are 3 sizes, 8 mm for the lines to and from the dryer, 6mm for most other places and also 4mm (i only spotted one 4mm line coming out of the valve block, don't know where it goes or if there are more).
Click to expand...

Cheers for that - useful info!

Your comment about leaks on the o-rings into the valve block itself got me wondering if that is the source of my leak. I have a slow leak somewhere which causes the n/s rear to drop overnight. Having checked for leaks everywhere else (and replaced some dodgy pipe unions), I assumed it must be internal to the valve block so I've put it to one side for the time being as I thought I would need to overhaul the entire valve block, but I'm wondering now if my leak is just in one of these o rings for the pipes going into the block itself.

Unfortunately I can't see the block end of the pipes. Presumably one needs to remove the block from the enclosure to access these?

Guy
 
no just a lamp and maybe a box to stand on as you'll be looking over the top of the EAS box down the other side (inner, long side). there'll be I think 8 different tubes (from memory, 1 to each bag, 2 to the dryer, 1 to the tank and one thin one) going in plus a little white thumb-sized thingy which is the exhaust filter.
 
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rasheed said:
no just a lamp and maybe a box to stand an as you'll be looking over the box down the other side. there'll be I think 8 different tubes going in a little white thumb-sized thingy which is the exhaust filter.
Click to expand...

Hmm. Maybe I'll have another look then but I couldn't see any way of accessing the block end of the pipes going to the airbags without dismantling the eas box itself and as it's my daily drive I didn't want to get into it that far.
 
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