Xantia, Hyraulic hose between reservoir and HP pump

VertVega · Post by **VertVega** » 16 Nov 2009, 19:17

Hi, I've recently noticed some surface cracks on the hydraulic hose that goes from LHM reservoir to the HP pump.
They are only on the lower part, near accumulator. There's no leak and no sweat (yet)! I guess that'll not last for a long time.
I've measured connector pipe diam on the reservoir side but it's not possible on the pump side.
Also it seems that outer diameters of the hose are different at pump and reservoir side. Is that possible? Has anyone replaced this hose?

- Do you know the outer diameter of the connector which is marked in the pic below? (pic from eBay)
- Is it possible to use a fuel line hose for replacement (is it LHM resistant)?

Thanks in advance.

HDI · Post by **HDI** » 16 Nov 2009, 20:46

That hose will be the low pressure feed to the pump. The cracking is deterioration to the rubber caused by various factors like , heat , ozone , oil etc. All rubber deteriorates over time , the compound it's manufactured from determines how long it will resist the various environmental factors.

There are three main parts of rubber hose construction , the tube (inner part) , reinforcement and cover (the outer part). The inner resists the medium passing through the hose , the reinforcement resists the pressure or vacuum and the cover resists external conditions. In this case the cracking in the outer cover allows external conditions to affect the internal structure and the rate of deterioration increases. At some point it will fail , but when is impossible to predict. It can be seen as an early warning.

Regarding different sizes at each end , this often occurs with bespoke hose units made for OEM on cars. Each hose is made to a drawing specifically for each application , there is very little general purpose , by the meter hose used on modern vehicles. Many hoses are moulded to a specific shape with ends as required.

LHM is nothing more than a mineral based oil with specific properties for Citroen's application , any nitrile lined hose will resist it's effects. Any quality fuel hose will resist LHM.

DickieG · Post by **DickieG** » 16 Nov 2009, 22:21

Several years ago I enquired at a dealer for a price on the LHM pump supply hose, the cost then was £150+

VertVega · Post by **VertVega** » 16 Nov 2009, 22:23

Thanks HDI, you're

If that's a multilayer hose then it's not an urgent case. Cracks are only on the surface layer at the moment.
It might be the heat factor since it's side facing the radiator

As a precaution, I'm planning to install some shield there, like wire hose or cable protection hose.

The ends looked to be different size, pump connection side seemed to be slightly smaller in diameter than the reservoir side

I have to check it again day time.

VertVega · Post by **VertVega** » 16 Nov 2009, 22:26

DickieG wrote:£150+

I also recall reading sometimes ago that it has this shocking price! Did you buy it or how did you solve the problem?

I think I'll use a good quality fuel line hose when it is necessary

DickieG · Post by **DickieG** » 16 Nov 2009, 22:40

VertVega wrote:
DickieG wrote:£150+
I also recall reading sometimes ago that it has this shocking price! Did you buy it or how did you solve the problem?

I went to a breakers and cut the end off of a LHM hose (complete with bend and diameter reduction) from an XM then joined the two hoses together with a plastic connector from a local motor factor.

HDI · Post by **HDI** » 16 Nov 2009, 22:50

£150 is seriously outrageous !!!

The important end is going to be the reservoir end , that can't be changed. So whatever size that is determines the size of hose. The pump end can probably be changed by using an adaptor to match the reservoir end so the same size hose will match both ends.

If you can find out the reservoir end size I probably have some suitable hose.

VertVega · Post by **VertVega** » 16 Nov 2009, 23:00

Thanks for the tip DickieG, That's the most suitable and the best solution for this case.

HDI, I measured the reservoir end which was 13 mm. So inner diameter of a new (fuel line) hose should be 12 or 13.
But I'll check breakers.

HDI · Post by **HDI** » 16 Nov 2009, 23:06

Well if u need it I definitely have 1/2" oil hose in stock.

Pleiades · Post by **Pleiades** » 16 Nov 2009, 23:20

I allways use fuel hose for LHM pipe, it's ready available and if you need to join it, there are loads of plastic "T" pieces etc that are for water hoses.

A few lengths of fuel hose, plastic joiners and jubilee clips will drag you out of the poo on lots of occasions.

Regards.
Martin.

HDI · Post by **HDI** » 16 Nov 2009, 23:30

Yes , actually those joiners are available with a different size on each side.