Low Pressure Brake hose "Condensation"

[nitro_warrior]

I had to buy some new low pressure brake hose from the reservoir. Now a lot of places seem to have black hose that is rated for brake fluid rather than the blue stuff. Fair enough I thought and bought some black hose and fitted it. However now it's been on for a while the hoses get what looks like condensation appearing on them. It's hard to tell if it is brake fluid seeping through or just water condensation. Has anyone had any experience of this? My rudimentary science knowledge doesn't imagine it is condensation... Bit of a pest if I have to change all the hoses again, not sure who to trust either if they are claiming the hoses are suitable for brake fluid when in fact they are not.

[Editor]

It sounds suspicious. Is the level down at all?
I think the blue stuff is still available from the usual aftermarket places. I used the wrong sort several years ago, and it lasted about a year before failing and losing the reservoir fluid.

[s.unsworth]

For Brake Fluid it has to be EPDM Hose (Ethylene Propylene Diene Monomer) inner tube with aramid reinforcement.

To prove it for myself, as I had Petrol Hose of the correct size, I tried putting some in a glass jar full of Brake Fluid. It just dissolved !

When I did the Variant I managed to get proper Blue Hose but only slightly later when I did the Beetle it had all changed to Black. The Blue does look better.

The only Blue stuff I have found recently is NOS in the USA. Even the LP Brake Hose from Heritage is Black now.

I bought this on ebay. It is Black but it is the correct materiel for Brake Fluid

http://www.ebay.co.uk/itm/AN-4-AN4-AN04 ... 1796wt_910

[purplepeter]

A 'phone call to Merlinmotorsports or Demontweaks should sort you out some blue brake hose

[nitro_warrior]

For Brake Fluid it has to be EPDM Hose (Ethylene Propylene Diene Monomer) inner tube with aramid reinforcement.

Thanks for the suggestions. Think I will buy somemore stuff that claims to be EDPM. I'm not too bothered if it's black or blue so long as it holds the fluid! I got mine from ebay, can't remember what material it said it was only that it was suitable for brake fluid. I have left a little sitting in a jam jar off brake fluid to see what happens.

At the moment the fuel tank is out so I would prefer to get it sorted before that goes back in.

Here are some pictures of what mine is doing. The fluid level in the reservoir hasn't really gone down but then I can't imagine there is much leaking through.

[937carrera]

That certainly doesn't look like brake reservoir hose to me

Do any of these help ?

http://www.ebay.co.uk/itm/Reservoir-to- ... 753wt_1291

http://www.ebay.com/itm/7mm-ID-Blue-Clo ... _957wt_975

https://www.merlinmotorsport.co.uk/p/7m ... m-m-sph8-4

http://www.demon-tweeks.co.uk/motorspor ... cting-hose

http://www.mofoco.com/item/VW_BUG_CLOTH ... /2489/c161

http://www.sierramadrecollection.com/st ... ail&p=4737

Depends if you want to go for original or not..... you can be sure that the stuff from Merlin / Demon Tweeks will be the right stuff

[Editor]

I'm sure that's not the right stuff.

Have you tried a VW dealer?

It was originally supplied in 5m coils - I would be surprised if there wasn't some left. It seems to last practically for ever.

[937carrera]

One further comment. I suggest you fix this asap. The Saab 9000 has a known problem with the equivalent pipe which ends up causing a clutch master cylinder problem because of internal debris from the hose, result being loss of clutch pedal.

[Editor]

GSF do free home delivery. Go to www.gsfcarparts.com and order by their part number 657VG0750 . Don't bother buying it from that ebay advert! £10.74 for a metre of the right stuff doesn't sound bad.

[nitro_warrior]

Thanks for that guys. I think I will go for the Blue stuff and stick with what we know. Good to get it sorted before it becomes a real issue.

[s.unsworth]

Forgot to say, on my experiment of Fuel Hose in a jar of Brake Fluid not only did it dissolve the hose but it also turned the Brake Fluid black, so it obviously also changed the composition of the Brake Fluid. Definately not good.

[nitro_warrior]

Forgot to say, on my experiment of Fuel Hose in a jar of Brake Fluid not only did it dissolve the hose but it also turned the Brake Fluid black, so it obviously also changed the composition of the Brake Fluid. Definately not good.

Well mines been sitting there since Sunday so we will see what happens to mine!

I'm actually wondering if the condensation is water and because the brake fluid is hydroscopic it's attracting water from the air rather than brake fluid seeping out. It doesn't feel or smell like brake fluid... Either way its academic, neither scenarios are good!

[Editor]

That won't be happening - if the fluid is penetrating the hose, then it might absorb atmospheric water vapour and get wetter, but it can't attract through an impervious hose, like a magnet.

The metal pipes would take heat away better than the brake-fluid filled hose, so you would get condensation on that part first before the fluid-filled hose. I can't see any possible explanation other than fluid seeping through the hose material. Whether having done that, it absorbs water vapour and gets wetter, is possible.