How common are blocked rubber brake hoses?

Hi all,

Did a bit of work with SIL today on his 2001 Berlingo van and when we came to bleed the o/s/r brake, it wouldn't. Cracking various joints up-to the o/s/r rear hose suggested it *was* the rubber hose but we didn't get chance to change it today to prove it 100%.

Googling about suggests it's not unheard of but I've not come across it myself (especially on something that 'young' (we built the kitcar well over 20 years ago and that's still ok AFAIK))?

I just wondered how common it was to those 'in the trade' and if there are any particular circumstances that cause it?

Cheers, T i m

Reply to
T i m
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I have only come across one in 50 years, the only likely cause is damage, either twisting or crushing. The inner sleeve breaks up and acts as a sort of flap valve across the tube. Much more common is a blocked solid bleed nipple, did you remove it?

Reply to
Mrcheerful

I have only come across one in 50 years, the only likely cause is damage, either twisting or crushing. The inner sleeve breaks up and acts as a sort of flap valve across the tube. Much more common is a blocked solid bleed nipple, did you remove it?

I too have only seen one, in hundreds of cars I've worked on. It was an old Sierra, I had replaced rear shoes and cyls, and like the OPs one, it wouldn't bleed properly, only the slightest trickle came out, and this was after I'd made sure the bleed nipple(new with the cyl) was clear. Eventually after probing with a bit of MIG wire, I cut the hose to bits to find the obstruction, and it was a bit of brass swarf, presumably from a pipe union, which had got half way down the hose and then dug into the wall of the hose. I assume it had been somewhere in the system since the car was built.

Steve

Reply to
shazzbat

Yes, my mate has only seen two in a similar number of years.

'Crushing' ... I wonder then if the hose clamp might have done it then? 'Final straw' or summat? We clamped the n/s when we did that and that was ok (as I have done many times before etc)?

I did (I removed the (new) nipple completely), along with undoing the hose union to the new slave cylinder, in case there was a manufacturing fault in that (however unlikely).

We got fluid on the input and exit of the brake compensator for that line but nothing at the slave cylinder. There is only about 30 cm of steel hose from the compensator to the rubber and the same again of steel down the rear suspension arm.

He's only just got the van and it had been only lightly used be the PO over the 10 years he owned it. We knew the rear brakes would need looking at and the other day (and before we got chance) the o/s/r locked up whilst parking and it was one of the linings had delaminated from the shoe. Whilst checking the other side we noticed the fluid leakage so changed both slave cylinders and (all) shoes while we were at it. The PO had mentioned that the handbrake can stick on if left on for an extended period but that was typically on the n/s (the one that was leaking). I think the 'leak' was brought about by it being used after being laid up for nearly a year?

We were (just) able to get to and crack open the connections to both ends of the o/s/r rubber hose but didn't try applying the brake at that point (running out of time and just wanted to see if we *could* undo the joints. It looks like the rubber hose is held in place (well, prevented from rotating) by splines along the hose end fittings where it pushes into the brackets at both ends (it looks like it's held *in* by the rubber to steel hose joints themselves)?

As I say, we didn't quite get that far and I'll get him to check the HBOL in the hope it covers such.

Cheers, T i m

Reply to
T i m

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We also got that on the new slave on the n/s but that was 'fixed' by putting some weight back on that arm (the fluid was only *just* trickling out the bleed nipple). Now, I / we put that down to the brake compensator (it bled freely when we put weight back on the arm) but what if the n/s hose was also starting to fail (or some other blockage / issue that could be affected by the movement of the rear suspension arm)?

I wouldn't have thought that something like that would block a high(ish) pressure hose on it's own though (but believe you when you say it did etc)? Did the swarf damage the lining that then failed or is the bore really that fine?

I had some swarf (half a turn of thread) bring my CF Camper to a halt but that was in the fuel line and got under the float jet. ;-)

Cheers, T i m

That just reminded me that in the 23 years I owned my 2L Sierra Estate it only let me down twice. Once was the o/s/f caliper seized and the other was the cambelt breaking. Luckily (it was a safe engine and) I was near to home and a new one fitted and I was on my way in under an hour. Oh, and a clutch cable snapped but I carried a spare, fitted it on the side of the road and went about my business. ;-)

Reply to
T i m

I keep on reading about it like it's common. I've personally never seen it.

Reply to
Dave Plowman (News)

So do you think a hose could be damaged (blocked) by the use of one of these:

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FWIW, I was on the phone when SIL fitted the clamp (although I was watching him) and I *may* have suggested he didn't do it up fully (if he had, I didn't really look). I did note he had the hose in at the hinge end and I think there is a gape there that might help prevent over doing it?

On the n/s I did it and used one of these:

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Neither side lost any fluid from the pipe when we disconnected them from the cylinder (but then that might have been the case anyway because of the brake balance / compensator)?

I have used both previously many times and never had any issues.

It may yet turn out to be something else ... ;-)

Cheers, T i m

Reply to
T i m

there will usually be a spring clip to hold the end of the hose in the bracket.

Reply to
Mrcheerful

In a way, it's kinda academic. The hose is clearly buggered, so it needs replacing.

Reply to
Adrian

Ok thanks, I'll see what we can see. Looking at the hose there is no groove or anything under where the hose might seat in the bracket so I assume it must hold it down via a small rib over the top?

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(Both ends are the same)

Cheers, T i m

Reply to
T i m

I would expect that the clip would hold the raised ring on the hose against the lug on the car. Unless there is something goes between the nut on the steel pipe and the bracket, there must be something to hold the ribbed section in the bracket, friction would not be enough.

Reply to
Mrcheerful

I think I'll only be fully convinced of that when I've taken it off and checked it out. ;-)

I've observed what should be happening but isn't (when trying to bleed the system). I've observed fluid coming out of joints when cracked before the hose but believe it was working before we did what we did (possibly applying the hose clamp). What I don't know is if these things recover on their own when they fail in this way (assuming that is what has happened etc).

This is all based around the thought that such things seem to be pretty rare so I'm keeping my mind open till I actually get the hose off (and of course replaced in any case). ;-)

Cheers, T i m

Reply to
T i m

Understood.

From memory (and in less than ideal conditions) I think I saw what could have been a 'spring bridge', a thin steel thing between the 11mm nut on the union and the underside of the bracket, providing some tension holding the hose down into the top of the bracket from underneath.

Cheers, T i m

Reply to
T i m

One thing I did find recently was that VAG have started to use thinner flexis that must not be clamped, the tubing is very hard and remains crushed if you do try and clamp them.

Reply to
Mrcheerful

That sounds like the sort of thing, it doesn't need to be much, just enough to hold it down in the bracket, not like the way it used to be done, with a GBFO nut. I have two of those to change on one of my cars this year, and the steering rack has to come off to get enough access to get spanners on, it isn't even feasible to cut the bloody things off, I bought the hoses 5 years ago, I really must fit them this year !!

Reply to
Mrcheerful

Interesting (how things change after being 'one way' for a long time). ;-)

Cheers, T i m

Reply to
T i m

Yeah, that looks like about all it would do.

Well, I don't know which is worse yet as I've never had to take one of this type off before. I think I have the GBFO type on the Mk2 Escort based kitcar, where they fix to the bracket on the strut and the inboard one over the front chassis. Don't they also just have two flats on the hose_end_fitting?

Dontcha just love that sort of thing / design ... (not).

Hehe.

I have been in a similar position re tyres on the kitcar (re not actually getting round to sorting them). It is a 'Jeep' style and one of the few things it does well (well, better than most other std saloon cars) is manage some muddy tracks and trails, mostly because of the reasonable ground clearance, the, 50/50 weight distribution, lowish gearing, 14" wheels and the 80 profile M+S tyres. Those sort of tyres also 'look right' on something like that. But finding 185/80/14 M+S tyres at a reasonable price (that aren't 6+ ply) isn't as easy as it was when we built the thing over 20 years ago. So every so often I start looking into it ... and considering getting some wheels made that both fit the car and offer tyre sizes more easily found in an M+S pattern (16" rims?) and every time so far have given up. Now though we really could do with getting it back up to spec so the hunt will have to start again.

Cheers, T i m

Reply to
T i m

you could widen your possibilities on the rims you have by going to a

195/70 x 14
Reply to
Mrcheerful

Ok thanks, I'll check that out.

The 'corner' of the existing 185/80/14's sit pretty close to the bottom spring cup so whilst a 195 is a touch wider than a 185 (well,

10mm, 5 each side) it's ~23mm smaller diameter so that might just put under the cup rather than beside it. The rears have plenty of room in most directions.

SIL was thinking of putting a new set of tyres on the Berlingo and so there could be a 165/70/14 I could at least fit to a spare rim and see how they look.

I was talking about wheels elsewhere and the thought that the wheel should closely fit the centre boss on the hub and therefore support the weight of the vehicle, rather than it being just down to friction between the back of the wheel and hub and the studs etc.

The suggestion was that this 'older cars' didn't typically have the close interference fit with the boss we often see today and therefore that may open up some alternative wheel options for me on the kitcar.

Cheers, T i m

Reply to
T i m

I have run a light car with huge wheel spacers that gave no centre location at all, that had no trouble in many thousands of miles and was used very hard.

Reply to
Mrcheerful

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