Leak from front suspension - strut return pipe

Frequently asked technical questions and common modifications/improvements
Mickey taker
Over 2k
Posts: 3209
Joined: Wed Apr 01, 2009 10:38 pm
Location: M K

Leak from front suspension - strut return pipe

Post by Mickey taker » Mon Jan 23, 2012 6:33 pm

came back to the car this morning after dropping the kids off at school to find a gooey mess all around the nearside front wheel .
on examination a strut return pipe had slipped off of the metal pipe it normally go's on to.
firstly is it best to lop a bit of pipe off the end before putting it back on the metal pipe ?
secondly should there be anything securing the rubber pipe to the metal one or is it just a push fit?
and thirdly what could have caused it to pop off in the first place ?
1991 BX Meteor 1.6

light travels faster than sound, thats why you look intelligent and then you spoil it all by opening your mouth !!!!!

User avatar
rmattila
BXpert
BXpert
Posts: 414
Joined: Sat Dec 25, 2010 5:00 pm
Location: Finland
x 1

Post by rmattila » Mon Jan 23, 2012 6:50 pm

There's no securing, and the popping off may be caused by too high leakage rate through the nylon ring seal in the suspension cylinder.

http://www.rmattila.com/images/remontit ... ppa_avaus/
http://www.rmattila.com/images/remontit ... usitolppa/
Speechless quad lying flat on his bed, communicating by moving eyes.
BX Van 1.9D -90 Gone.
BX Van 16S -90 For sale.
BX Van 1.9D -90 (Earned!) Gone.
BX Break 1.9D -90 (officially a "5 seat van" since 2005) Waiting to be towed to a new home.

Defender110
Over 2k
Posts: 5861
Joined: Wed Dec 16, 2009 8:02 pm
Location: Radcliffe, Gt.Manchester
x 19

Post by Defender110 » Mon Jan 23, 2012 7:32 pm

and no don't lob any off the length, it needs the length to flex up and down easily with the suspension.
Kevan
1987 Citroen BX MK1 diesel estate.
1997 Mercedes C230 W202 - daily driver.
2010 BMW X1 SE 2.0D Auto - Her indoors daily driver.
2003 Land Rover Discovery TD5 - hobby days and camping.
1993 Land Rover Discovery 300tdi 3 door - in need of TLC

bx petrol auto saloon
BXpert
BXpert
Posts: 477
Joined: Mon Aug 22, 2011 11:50 am
Location: Tonbridge KENT
My Cars: Citroens SAABs and Vauxhalls
x 2

strut return pipe.

Post by bx petrol auto saloon » Mon Jan 23, 2012 7:39 pm

Dear Susan.
I had to do a return pipe on mine when I first got her, I would only
lop a bit off first if you have plenty of spare lenght to do that. :wink:
Then you do need to lop a bit off, as original hole in the rubber pipe
will be a tad loose, if you cut it off it will make it a tighter fit onto the
metal pipe, which it needs to be :)
What I have done on mine, is I have put small black cable-ties, on
both ends of the rubber pipe, where they join the metal pipes, for added
security and also, so that I know which ones I have renewed 8)
Hope this helps :wink:
Vince.
Passion Hydropneumatic Citroen,s

Cars;- 1993 White Citroen BX 1.6 TXi petrol
saloon auto with air-con & ABS.
47,594 Miles from new.
Owned for 3 years sorned.
1988 Silver SAAB 900i 2.0 8v F/lift,
saloon 5sp with 3 spoke Ronals,
69,000 Miles from new.
Owned for 15 years T & T.

Mickey taker
Over 2k
Posts: 3209
Joined: Wed Apr 01, 2009 10:38 pm
Location: M K

Post by Mickey taker » Mon Jan 23, 2012 7:54 pm

i was only going to nip off a couple of mm to remove any flared rubber at the end to "take up the slack" the cable tie idea was my next option, thanks guys
1991 BX Meteor 1.6

light travels faster than sound, thats why you look intelligent and then you spoil it all by opening your mouth !!!!!

User avatar
Way2go
Over 2k
Posts: 7278
Joined: Fri Jan 13, 2006 3:15 pm
Location: RCoBerkshire
x 2

Post by Way2go » Tue Jan 24, 2012 3:02 am

If your pipe has "blown" off as mentioned, you are probably passing too much fluid on the strut and it has or is close to totally failing. I had a strut totally"let go" and not funny when you are miles from home. :shock:

Shorten pipes and use cable ties at your peril. If the strut is failing you will blow the octopus apart by the use of cable ties allowing too high a flow rate to reach it. :(
1991 BX19GTi Auto

Mickey taker
Over 2k
Posts: 3209
Joined: Wed Apr 01, 2009 10:38 pm
Location: M K

Post by Mickey taker » Tue Jan 24, 2012 8:36 am

ah ok, I am taking all of this on board, how do I test the strut, have been doing about 360 miles a week in the car and until now the suspension seems fine raises and lowers to all settings etc. Should I double check the pipe is on properly, refill the lhm and seeif it happens again ?
1991 BX Meteor 1.6

light travels faster than sound, thats why you look intelligent and then you spoil it all by opening your mouth !!!!!

User avatar
Way2go
Over 2k
Posts: 7278
Joined: Fri Jan 13, 2006 3:15 pm
Location: RCoBerkshire
x 2

Post by Way2go » Tue Jan 24, 2012 12:38 pm

Basically, the strut should be passing very little (drips) into the return and not a flow of any sort. This is why the returns are called "leak-offs".

If you have a flow, the strut internals have failed. Testing for flow needs to be done statically (engine on, suspension normal) and dynamically (car driven over undulating ground). For the dynamic test you will need to collect fluid in say a plastic bag from the returns to see what is what. The dynamic test is important because the larger leaks may occur if you have wear ridges inside the strut and the seals cannot bridge them in that position.
1991 BX19GTi Auto

User avatar
rmattila
BXpert
BXpert
Posts: 414
Joined: Sat Dec 25, 2010 5:00 pm
Location: Finland
x 1

Post by rmattila » Tue Jan 24, 2012 12:46 pm

There are two pipes, and the idea is that one works as a lekage return, while the other is a breather needed to enable the strut volume to change according to the suspension movements. There is a small metall ball acting as a check valve in one of the pipes, supposedly making that pipe to function as the return line, while the remaining one should flow back and forth.

Very difficult to verify whether it actually works that way, but that's how it is said to be designed.
Speechless quad lying flat on his bed, communicating by moving eyes.
BX Van 1.9D -90 Gone.
BX Van 16S -90 For sale.
BX Van 1.9D -90 (Earned!) Gone.
BX Break 1.9D -90 (officially a "5 seat van" since 2005) Waiting to be towed to a new home.

User avatar
Way2go
Over 2k
Posts: 7278
Joined: Fri Jan 13, 2006 3:15 pm
Location: RCoBerkshire
x 2

Post by Way2go » Wed Jan 25, 2012 4:13 am

rmattila wrote:There are two pipes, and the idea is that one works as a lekage return, while the other is a breather needed to enable the strut volume to change according to the suspension movements. There is a small metall ball acting as a check valve in one of the pipes, supposedly making that pipe to function as the return line, while the remaining one should flow back and forth.

Very difficult to verify whether it actually works that way, but that's how it is said to be designed.
I was of the understanding that fluid flow was in the other direction. :?
I believe the idea is that the ball valve allows air (& any latent fluid in the return system) to be drawn into the strut as it lengthens then closes as the strut compresses causing any leakage fluid to be expelled from the other leg. However it may not be as effective as intended and the pattern strut leg as sold by GSF does not contain any ball valve. The original leak-off returns as sold by the dealer still contain the valve so according to the above theory should act similar to a crude pump in the system.
1991 BX19GTi Auto

User avatar
MULLEY
Over 2k
Posts: 8375
Joined: Thu Jun 22, 2006 11:10 pm
Location: Derbyshire
x 3

Post by MULLEY » Wed Jan 25, 2012 8:34 pm

Never seen a ball in a strut return pipe in my life, never knew there was supposed to be one.
2002 C5 2.0 HDI Estate - Remapped - It goes better
2011 Mini Cooper D Clubman - it does over 60mpg
1992 TZD Turbo - SORN - slowly getting there
1991 Gti 16V - Blaze is back on the road since 2008
1990 Gti 8Valve SOLD - looks like it's been scrapped
2002 Mini Cooper S - SOLD - i miss this car
1992 TXD - Scrapped in March 2014

I'm not just a username, i'm also called Matthew.

Brian
BXpert
BXpert
Posts: 441
Joined: Sun Jan 08, 2006 5:53 pm
Location: Bedfordshire UK

Post by Brian » Wed Jan 25, 2012 9:56 pm

here we go then:

Image

Defender110
Over 2k
Posts: 5861
Joined: Wed Dec 16, 2009 8:02 pm
Location: Radcliffe, Gt.Manchester
x 19

Post by Defender110 » Wed Jan 25, 2012 11:03 pm

MULLEY wrote:Never seen a ball in a strut return pipe in my life, never knew there was supposed to be one.
Same as this, mine flow both ways, never seen anything like the picture of Brians???

EDIT: to lube my struts I pump LHM out of an oil can into one leg of the return pipe until it comes out of the other leg, no one way valve stopping progress?
Kevan
1987 Citroen BX MK1 diesel estate.
1997 Mercedes C230 W202 - daily driver.
2010 BMW X1 SE 2.0D Auto - Her indoors daily driver.
2003 Land Rover Discovery TD5 - hobby days and camping.
1993 Land Rover Discovery 300tdi 3 door - in need of TLC

User avatar
Way2go
Over 2k
Posts: 7278
Joined: Fri Jan 13, 2006 3:15 pm
Location: RCoBerkshire
x 2

Post by Way2go » Thu Jan 26, 2012 12:51 am

Defender110 wrote: EDIT: to lube my struts I pump LHM out of an oil can into one leg of the return pipe until it comes out of the other leg, no one way valve stopping progress?
I just checked the recent genuine spare I have in reserve and it would seem that the ball valve has been discontinued in these too. There used to be a "bulge" in one of the legs which is not evident now. :(
1991 BX19GTi Auto

RxBX
Over 2k
Posts: 2241
Joined: Wed Jan 28, 2009 11:51 am
Location: DERBYSHIRE

Post by RxBX » Thu Jan 26, 2012 1:12 am

MULLEY wrote:Never seen a ball in a strut return pipe in my life, never knew there was supposed to be one.
Brian wrote:here we go then:

Image
Matt this has all been covered before !
You've obviously forgotten (or have not got the memory of an Elephant like me :lol: ) THIS comprehensive thread (Which you even made a post in) which Brian hosted the same photo showing the plastic valve unit as /\ ?

Then there was THIS thread not too long before the one /\ , in which again you'd taken an active part, by posting in it !
In which I'd linked up into 'Rob Smith.plus.Com' site (at the time it did work showing the same part as in 'Brian's photo /\), but I've managed to find another foreign site (Czech maybe) which I've linked up (below for you and others) to see !

___________________________________________________________________________________________________________

On MK1 models (and early MK2's) the strut returns pipes where made up of five components (Ref. to THIS PDF P8/45) .

#1 Rubber strut saddle (The bit the you strap onto the strut leg with a S/S strap) or Kevans alternative (From BEAL-UK-Ltd as in THIS thread)
#2 Plastic valve (Annotated item11 on PDF) 'A' - over-flow/return pipe.
#3 Plastic push in/on (Plastic straight pipe) 'B' - vent-pipe.
#4 Rubber pipe from (#2 /\ ) to inner wing (push on) steel connection point (Note ! this is not shown in the /\ PDF) .
#5 Rubber pipe from (#3 /\ ) to inner wing (push on) steel connection point (Note ! this is not shown in the /\ PDF).

The (Five piece configuration) IMHO is a better design than the 'All in one' later rubber replacement, as its only a 5 minute job to just replace the length of rubber tube that bridges the front struts across to the inner wing static steel push on connection points when they split/fracture and pi$$ LHM all over the place !
_________________________________________________________________________________________________________

Also note that on the 'All in one' configuration they originally DID have a ball bearing fitted into one side of the rubber chamber to provide the 'valve feature' !
I don't know if you currently ordered an O/E from Citroen that it would come with the Ball bearing fitted (perhaps someone of the forum could confirm this if there recently bought one ?) as you can just hear it rattling about if you had a new one to hand, by giving it a shake (No jokes please :wink:) but most non O/E (after-market) ones never had the ball bearing fitted !

I've got a brand new spare pair of strut return pipes from GSF (which I've just given them a shake) and no rattling can be heard !

______________________________________________________________________________________________________

I was just about to press the 'Submit Button' but had a quick check to see if they'd been any more/new posts in this thread and noticed 'Way2go' posted who now answered the question I've asked above (Whilst putting my post together) so as I going to bed I can't be bothered to change what I've already typed up !
Way2go wrote:
Defender110 wrote: EDIT: to lube my struts I pump LHM out of an oil can into one leg of the return pipe until it comes out of the other leg, no one way valve stopping progress?
I just checked the recent genuine spare I have in reserve and it would seem that the ball valve has been discontinued in these too. There used to be a "bulge" in one of the legs which is not evident now. :(
I hope now that this topic is once and for all cleared up (AGAIN) !

Goodnight

:lol:

RxBX

For Brian, Please note that the image in the FCF LINK seems to have gone astray (possibly since the FCF-Forum/template was modified) ?

P.S. Another useful LINK I came across (Putting all the /\ post together) :wink:

.