12 replies to this topic

[paul_s]

My beloved has failed its MOT, surprise surprise  :-(

 

Apparently it failed on rear brake imbalance and emissions. I've been told by the garage it needs a new brake compensator valve, which they've quoted at £183 + VAT plus an hour's labour to fit. 

This seems like an extortionate amount to me, but is that reasonable to charge? Is there anywhere I might be able to get the compensator valve (I have no idea what this is!) for less?

 

Emissions is less of a worry as it may just be a loose joint (also the cat is a bit dented..)

 

Oh yeah, it's a '97 MPi if that helps…

Edited by paul_s, 04 April 2014 - 01:41 PM.

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Thats a terrible price on the valve! www.minispares.com/FAM7821.aspx (less your TMF+ discount)

If it even is that. I'd be inclined to get the rear shoes adjusted up and go from there

[DomCr250]

Agree with Simon 100%, never seen or heard of the compensator valve failing - it's almost a foolproof part.  And is so close to the brake master cylinder it should not suffer with internal corrosion.  As Simon says (sorry!) make 100% sure the rear shoes are adjusted correctly, it's so simple most people adjust them before it goes in for the MOT.

[paul_s]

Wow, that's a hell of difference in price!

The history is: last year it failed on the handbrake and a brake imbalance. They 'cleaned up' the rear drums and it passed.

This year it had an 82% brake imbalance (again, no idea here). On 'investigation' that's what they found, the compensator valve.

 

Big problem is, I'm about to move house so I don't have a lot of time to investigate / fix; the garage sort of has me over a barrel.

 

Worth asking about the emissions then though - they've said 'all the values are all over the place'. From this vague analysis, could a lambda sensor / dodgy cat be at the root? I know it's not much to go on, but before I phone them back and take my weekend up fixing it I'd better check!!

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The emissions they should be able to give some idea of the fault. Lambda is the obvious, but if the cat has failed they should be able to tell you that (I would hope!)

[Fast Ivan]

ask for the emissions print out and post it up, we might be able to help, are you getting any running problems?

Is the car in good serviceable condition?

and did you give the car a good drive before the emissions test?

As for the brakes, I would get under and in and have a look

[paul_s]

I drive the car on average once a week to work and back (15 mins each way). It's always had a slightly rough idle but nothing that I've really noticed. It's also a 15 min drive to the test centre, so I don't know if that counts as a 'good drive'?

It's not bad serviceable condition I would say - a bit tappety but I keep an eye on the oil, fluids etc..

 

My biggest problem is time - with moving in a week, I'll have no way of transporting it without an MOT so I need to try and fix it this weekend I suppose. 

I'm not bad mechanically and have no problem with tackling jobs, but I don't have a lot of experience so while I can replace stuff, identifying what needs replacing is not my strongest point..

 

Maybe I should take it back and have a look over the weekend, then maybe take it somewhere else to get it MOT'd once I've had a chance to look at it. I'll get the 

 

 

With the MOT now expired, am I legally allowed to drive it back home to work on it? It'll be in the garage so off the road..

[jamesmpi]

My mpi is a bugger on emissions, but not had them "all over the place" plus I had a fuel boost valve problem (which is more trouble than its worth). Is you engine modified in anyway?

 

I'm wondering if you need to take it for a good hard run up a motorway/dual carriage way to get the CAT / exhaust nice and hot. 15min drive isn't really long enough IMO......Without seeing the emission read out I would suggest changing the Lambda. Might also be worth getting a fault code read done too just in case there is something else playing up.

 

On the handbrake front, it maybe worth checking your quadrants to make sure they are not seized. My mpi has failed on brake efficiency  which was due to a leaking cylinder. They also tightened up both cables which helped.

[paul_s]

Right, well I've had a chat with the garage, and they've already spent (charged) an hour's investigation which has led to the compensator valve not working (no fluid coming out of one side apparently). As it's in bits at the minute I've beem spineless and agreed to get a new valve which they'll fit, but I'll get the car back after to have look at the emissions etc. If it's a lambda sensor I'm sure my skills will stretch to that..

 

So Simon, I shall be over to Potters Bar in the morning to purchase one of your finest valves!

[[email protected]]

Right, well I've had a chat with the garage, and they've already spent (charged) an hour's investigation which has led to the compensator valve not working (no fluid coming out of one side apparently). As it's in bits at the minute I've beem spineless and agreed to get a new valve which they'll fit, but I'll get the car back after to have look at the emissions etc. If it's a lambda sensor I'm sure my skills will stretch to that..
 
So Simon, I shall be over to Potters Bar in the morning to purchase one of your finest valves!

No problem, we have plenty in

[Racing Gold]

I have had a couple of the valves pack up on customers cars in the past 6months, don't know if it is down to the age of some of these cars now. No good the garage saying fluid is not coming out one side, that is quite common, again on cars which are getting older and have the original rear rubber hoses. If I suspect the valve on the bulkhead, the final check is to undo the feed pipe to the T piece on the rear subframe. No fluid then i found valve had packed up. I have also had several cars fail emissions on MOT when customers have taken cars in. In all cases, they have driven a few miles to the MOT station then left it there. At sometime during the day, the MOT tester has started it up and driven it in and ccarried out the emissions test. This is a waste of time as it is cold. A mini friendly MOT tester is required who knows that the cat on a Mini is different because it is so far back from the engine it does not get hot. It is why the more modern cars had their cats bolted up near the manifold where the heat is, hence they have little trouble with emissions. This is assuming no code reader faults. I tend to drive customers cars along the motorway or fast bit of road, (with their authority) with the final bit to the MOT station, using 3rd gear. A car that had failed at one of the above stations, usually passes at the Mini friendly one I use. If it still does not quite make it, the tester usually gives it about 4high revs to clear things and it usually settles down and passes the emissions despite very high ones when originally tested. If it does not and HC's are high, more often than not, if cat is the original Rover item,that is the fault and changing it solves the problem. I have also found that some cats out there are not that good. I now only fit Bosal replacements, tend to be dearer than some but hey!

[Jordie]

The valve caused me to have very low rear brake readings, but they werent imbalanced.

 

Do you have a copy of the readings? Imbalance to me sounds like something else, not the valve

[paul_s]

Morning all, 

 

I'll post up the readings later for reference (left them at home) but I have the car back and all is better. The cat did have some hefty dents / scrapes in it so might have been related to that. Time to remount the exhaust, and sort the rear suspension out too I think…

 

One thing I will say though, it does actually feel a lot better. The car used to be a bit jerky in 2nd around 2k RPM, but it's a much smoother drive now. I put it down to the car being old or a worn engine mount, but it seems it might've been the sensor or something.

 

I've decided it's time to try and find somewhere I can store the car / work on it, as it's ridiculous having to pay for someone else's labour when some of it I could do myself!

 

Thanks again for all your advice