rust prevention

[captainhaddock]

I finally got up to the job of changing the fuel filter. Ridiculous spot to place one, but there we are, it's a citroen after all.
I do not think the old one was ever changed (so much for old service bills) unless dealers use these special clips around the hoses, especially in that difficult to reach area .
I doubt it.

Anyway, since the exhaust box is off now, I decided to see to any rust issues. There is very little and what I found is treated and will be wax oiled tomorrow. Some rust on the bigger diameter left pipe going into the left suspension thing. It suffers more there because of the heat from the exhaust? Are these pipes still for sale I wonder?

My question is where this famous rot spot behind the rear subframe is. I read somewhere, water can get trapped? I have looked, with small mirror etc. but haven't lowered the subframe, too lazy. Should I still do this? All pipes look as new of what I can see.

[Peter.N.]

The top of the subframe is where most pipe failures occur, I spray it with oil every year, I haven't had one fail since. Put oil into any hollow sections before you put the waxoil in, the oil will creep into the seams which is where the rust usually starts, the waxoil can set before it gets there.

Peter

[citroenxm]

I doubt pipes are available anymore however the thicker hydractive pipes that the xm use to the corner struts are quite meaty and rather thick walled.. they need to be rusting for some time before they really pop...

in the unlikely event though i have a good few on collection to keep me going and anyone who may need one in an emergency...

id give the rusty pipe a good sand papering rub down and re paint it with under seal...

as for subframe pipes if they start to rot IN a pipe clip no amount of under seal will help. they really need poppin out and rubbing down.

subframe lowering is not that daungting... have the car supported across the sill edge and rear floor area and have the jack under the frame.. remove the two frame bolts and lower the One side... have a good look at the pipes then lift it back up and re fit the bolts...

[captainhaddock]

Thanks, I will try and not be lazy tomorrow evening. Dont mind lowering the subframe if I find time. So those pipes rust IN the clips. I have cleaned and treated the thicker hydractive pipe, so will waxoil them as well tomorrow.