A steel brake pipe "exploded" during the MOT test. Corolla owners beware.

[olddriver]

A steel brake pipe under the car "exploded" during the MOT test, I was told that the brake pedal was heavily loaded in a similar way to that in an emergency stop.  The garage will replace the pipes with copper.  I was also told that any corrosion of the pipes cannot be seen during the MOT test because there is a plastic cover over them.  Can anyone please confirm that there is a plastic cover over the brake pipes under the car, I've looked in Haynes but there are no pics.  

 

Perhaps I should have checked the pipes before because when I replaced the rear brake cylinders three years ago, I also replaced the adjacent U shaped brake pipes, partly because of corrosion but also because I thought that I may twist and damage them when replacing the cylinders.

 

Maybe it was a Godsend because it could have happened to me during a real emergency stop, and if I was involved in an accident it is possible that my Insurance company would not have covered me!

 

Perhaps anyone with an old Corolla like mine should check their pipes too.

[oldcodger]

HI,

Cannot say about your '98 motor but having recently checked mine over for the MOT there are certain coverings over the brake pipes but not all areas, though at 10 years old its hard to see clearly.

Having replaced my flexible hoses last year, where they connect to the rear brake pipes seems a corrosion point, though little apparent protection on the last few inches of pipe ?

At nearly 20 years old, if you are consdiering keeping the car then I would suggest replacing the lot; what price safety  ?!

In this months Car Mechanics magazine there is a 'workshop tale' where the garage proprietor says he does not use copper pipe, but Kunifer/Cunifer which is a mix of copper and nickel, plus a bit of iron and manganese, it does not  rust  and is more formable than copper etc etc

Seems quiet cheap and you can  also buy  'kits' for redoing the whole car, including tools etc

[olddriver]

Thanks oldcodger, yes I have asked them to replace all the corroded pipes.  The garage says they use copper because they are more formable than the Kunifer pipes.  They said that was especially the case when passing the pipes up over the petrol tank to save removing it, although on reflection I would have thought that was a bigger diameter pipe.  A long while ago, I used the Kunifer pipes and although they were easier to bend than steel, I still think that they were a bit stiff but I am not really sure.  Having used copper for microbore central heating pipes, they were certainly very pliable, but the brake pipe copper may be an alloy to make it stronger under pressure, so that may not be so pliable.

Edited August 31, 2016 by olddriver
Added microbore

[mickburkesnr]

I just put my Corolla (same age and model as yours actually) and it passed, but I went under the car with the guy and he commented on the rear of the car saying there was a lot of surface rust. I never even thought the about pipes back there. I might look in to the pipe work on mine just to check it and price it up accordingly.

Thanks for the heads up.

[Mike169]

Hi, I did MOT's on cars and yes some cars have brake pipes that are coated in plastic but not all. The plastic of course protects the pipes from the elements but of course traps any water that may of got it at one end of the plastic. Yes I have MOT'd cars, had brake pipes fail, had handbrake cables snap. Of course customers would try it on putting the blame on the garage for breaking their car but understandably after a sensible chat they'd see really it was due to the condition of the car as to why things fail during the test.

As for what type of brake pipes to change it with they are all much the same to be honest and it wouldn't bother me whichever was fitted to my car, you may find your local dealer can order you an original pipe which is already bent to the right shape so looks neater when the job is done but not many people do this.

[olddriver]

46 minutes ago, Mike169 said:

Hi, I did MOT's on cars and yes some cars have brake pipes that are coated in plastic but not all. The plastic of course protects the pipes from the elements but of course traps any water that may of got it at one end of the plastic.

Thanks, but it was my impression that the pipes are covered by a plastic panel/plate not a coating, but you could be right.

 

[olddriver]

1 hour ago, Mike169 said:

As for what type of brake pipes to change it with they are all much the same to be honest and it wouldn't bother me whichever was fitted to my car, you may find your local dealer can order you an original pipe which is already bent to the right shape so looks neater when the job is done but not many people do this.

The pipes from the dealer are not always bent, sometimes they are just straight but at least they would be the correct length.  However, the U shaped brake pipes adjacent to the Corolla rear brake cylinders were indeed formed to shape ready to fit.

Edited September 1, 2016 by olddriver
Added "but at least they would be the correct length".

[Mike169]

Hi olddriver, yes the brake pies themselves were coated in plastic, a bit like a thick straw if you like and the ones that are coated the coating normally stops say an inch before it gets to the union at the end so you can get a 'correct' brake pipe spanner on it, the spanner normally gripped the union on 5 sides so has a cut in the ring part of the spanner to slip it over the pipe. Of course not all DIYers have brake pipe spanners so just use a normal one instead which of course grips the union on less sides. If the union is say seized in a wheel cylinder just cut the pipe off short with decent side cutting pliers and use a 6 sided socket if possible to undo the union unless you are letting the garage do the work of course in which case you don't have to worry about this. Your experience just goes to show how important MOT's are, in this case may of saved your life!

[olddriver]

1 hour ago, Mike169 said:

As for what type of brake pipes to change it with they are all much the same to be honest and it wouldn't bother me whichever was fitted to my car, you may find your local dealer can order you an original pipe which is already bent to the right shape so looks neater when the job is done but not many people do this.

It occurs to me that if there is bare steel adjacent to the copper or Kunifer pipes then the pipes could initiate galvanic corrosion, dissimilar metal corrosion, on the steel.  Consequently if the underseal is not in good condition, the original dealer pipes would be better.

_______________________________________________________________________

Yes, your right Mike, my MOT may have been a life saver.

I'm stuck with the garage replacing the pipes because it is undriveable without any brakes.

[garethpaul]

yes, where the pipes run from the front to the back under the car, there is a plastic trim cover. This cover does have regular spaced holes in it, but it is not possible to inspect the full length of pipe without removing this cover - something they are not allowed to do in an MOT.

I put my car in for MOT last year, and it passed fine. Not 5 days later, one of these brake lines ruptured under this cover. The affected area was right where the pipe was attached to a clip, and you guessed it - there are no holes in the plastic trim where it fixes over the clips.

It was impossible to see this corrosion with the trim in place, and the rest of the piping viewed through the holes in the trim looked fine.

I wouldn't worry about galvanic corrosion. The pipe shouldn't be touching the body of the car anyway in the first place. Providing it is fixed securely in its clips, you will be fine.

[olddriver]

Update:

The pipe has been replaced and Garethpaul has explained the layout as I understand it.  The garage actually used Kunifer pipe, but could not get it over the petrol tank and that did not look corroded, so they left that in situ.  The brake pedal appears to be stiffer so maybe the pipe had been expanding under braking before.  When I have time then I will have a look.

EDIT:

The MOT actually stated that three "front to back" pipes were excessively corroded and dangerous.

[garethpaul]

excellent news.

In my case, the rest of my piping looked ok, so I only cut out the affected piece - about 4 inches either side of the rupture and joined a new piece in.

You may have had a little pinhole in the piping for a while which has allowed air to enter on the pedal upstroke making your pedal spongy. A bleed through with new fluid has removed all this air and made your pedal firmer as it should be.

[Mike169]

This is all good news and it could of got worse olddriver, things like the brake master cylinder can fail depending on how the garage bled the brakes so I think you have got off lightly. The repair they did is very acceptable and I support their idea of changing the damaged/corroded section of pipe, it can make a much neater job of it all. Mike.

[mickburkesnr]

Out of curiosity, and I hope I don't offend, but how much has the pipe replacement work cost you?

[olddriver]

3 hours ago, mickburkesnr said:

Out of curiosity, and I hope I don't offend, but how much has the pipe replacement work cost you?

For 4 hrs work, 18 units (I can't think what that would be other than feet) of brake pipe at £1.15/unit, 4 brake pipe nuts, and I unit (litre, I assume) of fluid, was £342.

If that is 18 feet then they must have replaced almost all of the pipes, so I am pleased. 

EDIT:

The MOT tester was female and I am a 6' 4" male, consequently the pipe could possibly have failed if I had just made a quick stop, never mind an emergency stop.

[mickburkesnr]

Doesn't sound too bad actually, especially as they're fitting it for you.