Archive for the ‘brakes’ Category

Dangerous to drive


It is not often that I feel the need to highlight something on the VT30 failure notice as being dangerous to drive, just recently I have had to use it for brakes and suspension faults. The first case being a pair of rear  leaf springs on a Ford Transit which had fractured at the anchor end spring eye, the only thing holding the spring in place being the weight of the vehicle bearing on the spring eye.

leafspring1

The spring can clearly be seen, from the rust “witness marks” to have worn away at the anchor bracket where it has been moving sideways.

leafspringAnother pair of items to crop up under the dangerous to drive tag was a a pair of front brake hoses on a Ford Maverick these had deteriorated so badly that the braided innards of the hoses were clearly visible

hose1

hose2

 

 

 

 

 

 

 

 

 

 

Earlier in the day a customer had brought us a Mercedes ML320 with a pad warning light on, and asked us to replace the front brake pads as he’d done the rears, or friend had, to save some cash.  Once we’d removed the wheels to replace the front pads we knew they were not the reason for the warning light being illuminated, so we turned to the rears to check the wear sensor wire, immediately noticeable was  the thread of a brake caliper bolt and therefore the lower end of the caliper was not secured and had broken the sensor wire, thus causing the light to come on.

nsrcal1

Had this been the upper caliper bolt it is quite possible that if the caliper had been caught by the wheel rim it would have caused serious damage to the wheel, the caliper and the caliper bracket, with the wheel quite possibly locking up .

nsrcal

Incidents like these are rare but unfortunately they do happen, which is why we have Mot’s, no matter how a good a mechanic you are, or think you are, another pair of eyes checking the work afterwards can be an extra safeguard for vehicles on our busy roads.

Brake pipes and hoses


A slide show of various brake pipes and hoses found on vehicles for test, in the  case of the leaking brake pipes,  the fiesta rear began leaking on test and the other (astra o/s) fractured and leaked as it was prised out of its support clip prior to repair.

This weeks crop


Several items of interest this week, the first is regarding seat belts and their associated mountings.

When a seat belt is attached to the seat, then the seat mountings are checked for security and corrosion in the surrounding area.

On checking a seat on a Ford Ka it was noted that the seat seemed to move a little more than normal when rocked lightly. As the mat above the seat mount was easily lifted, then a further check was simple and disclosed the securing bolt sat beside the seat bracket.

The vehicle presenter had no idea that there was a problem. The vehicle had been regularly serviced by the main dealer and as far as she was aware the seat had never been removed.

The second item concerns standards of corrosion repairs.

A Nissan micra in for MoT had previously had a repair to the rear sill because of corrosion, looking at the repair from outside the vehicle there were signs of welding with a thin skim of body filler and paint to tidy the repair up. The repair felt sound and didn’t “give” under thumb pressure.

Inspection from underneath revealed however that the bottom edge of the patch had had no weld applied at all. The testing standard for patch repairs requires that the repair should be seam welded along every edge.

The third item comes from a vehicle we had in for repair as the brakes felt spongey and was losing brake fluid. On inspection it was immediately obvious a rear brake hose was bulging, we’d had no need to apply pressure to see the problem.

The inner core ofthe hose had deteriorated and was allowing fluid to seep under the outer rubber covering, had it been on a front brake the outer covering would probably have split and caused a serious brake balance problem.

This second image shows how badly the outer covering had stretched when the fluid had seeped into it.

Corroded brake discs.


I’ve made several posts regarding corroded brake discs and what is an acceptable level of corrosion.

The description of reason for rejection rgarding disc condition is worded

“a brake disc or drum in such a condition that it is seriously weakened or insecure”

The first example shown below was seen on a 2003 astra rear, in this case the surface of the disc although corroded has not penetrated into the disc so that it is likely to break or crack, the brake performance however showed a slightly different story in that the performance suffered badly enough to affect the rate of application and to cause serious judder.

The following images are from a 2004 Renault Megane Scenic brought in for repair, the customer had heard a bang as she applied the brakes.

As can be seen from the below image, the brake pad is missing, the bang heard was the brake pad “escaping” from the pad carrier.

Once the repair was started the full extent of the problem was revealed, once the disc was removed the inner face of the disc was very severely corroded, and the inner brake pad was metal to metal, or in this example metal to corrosion, it appears the friction material had broken away on the inner pad too. In the image below we’re seeing the face of the pad that should have 1.5mm of friction material, and also can be seen is the way the surface of the disc has been flaking away.

I don’t know how long the brakes have been in this condition but I would have expected a grinding noise to be noticeable for a while beforehand.

Don’t shoot the messenger.


As above please, we’re only doing our job, for your safety.

We had a vehicle presented this week for test, on beginning the test the abs light was illuminated indicating a fault with the abs system, the only reason for rejection noted. As normal we contacted the young lady and explained that it was a fail for this reason.The young lady told us the light wasn’t illuminated when she left it but that it occasionally came on and stayed on for a day or two.we made the offer to plug in the diagnostics machine to read the fault codes and extinguish the lamp, if it stayed out we could then retest and issue a pass, or she could take it away and return when the light was out for retest. She chose the first option, we extinguished the light, made note of the fault codes for her and issued the pass. Fine you would think, job done.

However 40 minutes later I had a call from her partner accusing me of putting the light on ! When I explained the light was on at the beginning of the test he told me I was lying, at this point I handed the phone over to the boss who went through the same explanation with the same result.

Contrary to what some people appear to believe Mot testers don’t make up their own reasons to fail a vehicle, we’re not out to rip people off doing unnecessary work, it’s just not worth the damage to our reputation.

When the bill was presented with the diagnostics listed as free of charge, there were no thanks or an apology for her partner’s attitude.

Other items this week, a Ford Ka presented with a leaking brake pipe union, sometimes we find this after a brake pipe has been changed and not checked with the brakes applied. What was unusual was the brake pipe appeared to be the original and no signs of work having taken place to account for the leak.

Some new reasons for rejection have been applicable since the beginning of the year with regards to ball joint rubber boots. This one was on an 03 Corsa anti roll bar link.

“… a balljoint rubber boot deteriorated no longer preventing the ingress of dirt etc”

seen removed from the vehicle , yup I think dirt will get in there

steering, brakes and suspension


We’ve had a number of items crop up this week, the first was on a ‘w’ reg Ford Ka, quite a bit  of corrosion reared it’s ugly head, not really surprising bearing in mind it’s age, but we also found a steering issue

the universal joint at the bottom of the steering column was excessively worn, allowing ecess free play at the sterring wheel, approx 30mm rather than the allowable 13mm. As it was a vehicle with power steering the joint was not available as a separate item, necessitating a replacement steering column, fortunately we were able to source a second unit rather than having to pay the main dealer price 0f £300+ for a new unit.

Friday afternoon we had a rather worried young lady in as her brakes were making a funny noise, a visual check through the wheels revealed one of the pads  breaking up, once the parts were ordered and on their way a stripdown revealed 3 of the 4 pads friction material had separated from the backing plate.


The pads were about 2/3rds worn but the vehicle had been relatively unused for a month or two .

Saturday brought a different problem in. An 06 Astra  for test had a badly worn tyre showing the cords.

  Once I began to check the steering and suspension on the ramp the reason for the inner edge wearing so badly became apparent.


The ball joint in suspension arm was badly worn, when it was driven into the brake tester to check the brakes a loud clunk from the front suspension was heard, had the vehicle come into the workshop when the clunk was 1st apparent the tyre may have lasted a few months more.

The Vt32 Advisory notice.


Often when conducting an Mot the tester will notice an item that has deteriorated, but has not yet become bad enough to warrant a failure. In a few cases I’ve seen customers glance at the vt32 and immediately dispose of the advisory notice without consulting regarding  the necessary repairs.

There is a reason for issuing these notices and it’s not just to cover our backsides.

Two examples have arisen this week, in one case the handbrake had been advised (by me, in January) that the efficiency was only just passable, the vehicle returned to us this week to have the repairs carried out before taking the car away for a long weekend.

Checking in the roller brake tester the efficiency of the handbrake was down below 5%. A stripdown of the brakes revealed the brake shoes very badly worn and the braking surface of the drums severely corroded.

The second example could have had far more serious consequences, the vehicle had been tested elsewhere several months ago and the owner had been advised that a brake hose was deteriorated.

The brake hose split this week and resulted in a minor shunt, however the owner suggested that perhaps the tester had been overly lenient when the vehicle was tested and perhaps the test was in his words “dodgy”.

Did he complain at the time, or was he just pleased not to have another repair at the time ?

However he then asked us to blank off the relevant brake hose as he couldn’t afford to have the  repair done until the end of the month but needed the car for work!!

Fortunately he was able to come to an agreement with the boss and the repair was completed rather than allow the vehicle to continue on the road in that condition.

 

Fortunately the coming changes to the Mot certificate will prevent the vehicle owners from just binning the Vt32 on their way out of the testing station, so there will be a permanent reminder that work is required .


Flexible brake hoses and routing


We’ve had  a transit in for extensive welding and to replace a front suspension ball joint on a vehicle that had been tested elsewhere. Initially, when it came in, knowing that I’d have to complete a full test once the repairs were completed, I had a quick look around  underneath. I thought a brake hose had something amiss, however the hose had recently been replaced so at this point I didn’t pay a great deal of attention to it.

On removal of the front wheel to perform the replacement of the ball joint I noticed the flexible hose was severely chafed.

On closer inspection it was obvious the hose had been bolted to the suspension strut incorrectly and when the vehicle was in use the hose was rubbing on the wheel rim, in a fairly short period of time the hose would have worn through leading to a complete loss of braking to this wheel.

When testing I always  feel along the hose automatically in case of bulges not easily visible, but, better to have discovered it before testing it rather than during the test.

More worn out pads


We had a Peugeot 306 in for mot this week, one of the front tyres needed replacing so the owner got us to fit the spare, however on removing the wheel we  were confronted with brakepads almost to the metal.
the pads were so low that on one the friction material had begun to break away
fortunately the customer was on site so we were able to show him how bad they were and thus get his permission to replace the pads. With the wheel in place it was impossible to see how far down the pads were worn except to say they were close to the metal. Without being able to see the pads properly we could not fail them as the benefit of doubt must go to the vehicle presenter.

It seems that as times are getting harder more and more car owners are treating the Mot as a scheduled service, which is a little short sighted and perhaps dangerous as Mot standards are an absolute minimum standard required for safety.

Steering and brake pipes


Steering rack gaiters

One of the common reasons for rejection with regards to steering is a split steering rack gaiter, to check these thoroughly the gaiter needs to be fully extended with the steering on full lock, as sometimes without it being extended a small split may not be noticeable.

Once the boot is split water can enter and cause wear and corrosion to the ball joint at the inner end of the rack. In the past these rack end joints were not readily available other than from main dealers (at main dealer prices) so often the cheapest option was to have a reconditioned rack fitted.

Brake Pipes

I’ve written about brake pipe corrosion as a reason for rejection, another reason for rejection is if the brake pipe is kinked, such as this one 

found on the offside front of a 52 reg jaguar, this also caused brake imbalance as the fluid flow was so restricted.

Below is an image of how it ought to have been.

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