Front Brakes

[Redexcel]

Just had a call from my wife who had a scare whilst driving our 87 Excel - she says the car was pulling to the right under braking - then lost most of the braking power. She says it seems to be stopping OK now - will have a look when I get home from work but does anyone have any ideas?

I'm assuming there are some bubbles in the cables somewhere... and brakes are engaging on one side only, or unevenly.

Car was C-serviced in December with a clean bill of health except a small power steering leak.

Was it wet?
It sounds as if she may have locked up the front wheels.

[GavinTaylor]

My money is on a sticking right caliper.

Gvain

[dukeofpeckham]

Yep - looks like sticking caliper - loads of brake dust on the wheel and Madame reported a burning smell. Sounds like she boiled the fluid!

It could have been a lot worse! Looks like caliper rebuild or replacement

[Steve C]

The price I put on the parts alternative page was for "black stuff" ... these are just OEM replacement pads. Green stuff & Red stuff will cost more.

I used Red Stuff with my PNM 285mm kit at Castle Combe and they took all the punishment I could give them in the dry morning session with no loss of pedal or change in feel ... When I came in and parked up after the session it was noted by an Esprit friend that they were smoking slightly

[GavinTaylor]

My sticking caliper occured at a very inconvenient time (Dunno when might be convenient?), but, anyway, I happened to be reasonably close to a local club members tyre/brake shop.

He put the car on the hoist, pulled back the dust cover and gave it a squirt of brake fluid. We "exercised" the piston back and forth a couple of times (pads were out), put it back together and presto - not a problem since. He tells me it's quite common for the piston bores to become dry.
I'm just saying that caliper replacement may not be necessary and that a rebuild is relatively cheap and painless.

[Redexcel]

In my experience, a sticking piston is usually caused by a build up of crud and corrosion on the piston itself. The piston should be removed and cleaned. If there is any remaining corrosion that can be felt with a thumbnail (is this a rule of thumb ? ) then the piston and seal should be replaced.
And of course you need to do both wheels on an axle to keep the balance.

In view of the safety implications, you should always err on the side of caution.

[dukeofpeckham]

Thanks for your thoughts guys. The problem has completely cleared up now but I have booked the car in to the specialists for a check over anyway - as Paul says it's better to be safe than sorry - never know when it might happen again...

However... in the inimitable way my car has of coming up with surprises... it's now running on three cylinders only. A good revving failed to solve it. It's happened once before but cleared up after a bump start (a long story - knackered starter motor)

Anyone else get this? I'm assuming it's to do with partial flooding.

[Steve C]

Pull the plug leads in turn to work out which cylinder it is, then stop the engine and remove the offending spark plug .. if it's wet, there's probably no spark, if it's dry, there's no fuel ..

If the plug leads are old, I'd probably start with a set of plugs and leads over stripping down the carbs!

[Redexcel]

Pull the plug leads in turn to work out which cylinder it is, then stop the engine and remove the offending spark plug .. if it's wet, there's probably no spark, if it's dry, there's no fuel ..

If the plug leads are old, I'd probably start with a set of plugs and leads over stripping down the carbs!

When dealing with electronic ignition, don't just pull a plug lead with the engine running. If you do, there's a good chance you will kill the amplifier. You might also get a nasty shock if you are using an uninsulated tool or your bare fingers. More likely if the leads are past their best.

A safer method is....

Stop the engine and connect one of the plug leads to an old plug. Lay this on the engine securely so that the body is earthed. Then start the engine to see if the missfire is worse or the same. Stop the engine and repeat for the other cylinders until you find the duff cylinder.

Personally, before I did this, I would pull all the plugs and check for wetness. You can also do a compression test while the plugs are out.

[Steve C]

When dealing with electronic ignition, don't just pull a plug lead with the engine running. If you do, there's a good chance you will kill the amplifier.

Why will this kill the amplifier? How is the loading different to the coil & hence amplifier than having a duff lead?

You might also get a nasty shock if you are using an uninsulated tool or your bare fingers. More likely if the leads are past their best.

Good point, especially if it's a damp day ...

[Steve C]

Ouch, it sounds like you've had an expensive lesson!! I've never had to replace an ignition amp, and only a coil once on a car fitted with points around 20 years ago!

Perhaps I've got away with it by pulling leads off for only a second or two at a time - and maybe there's less effect on a dizzy car since the other three cylinders will still be firing wheras a wasted spark system could have a coil that doesn't discharge.

[Redexcel]

Ouch, it sounds like you've had an expensive lesson!! I've never had to replace an ignition amp, and only a coil once on a car fitted with points around 20 years ago!

Perhaps I've got away with it by pulling leads off for only a second or two at a time - and maybe there's less effect on a dizzy car since the other three cylinders will still be firing wheras a wasted spark system could have a coil that doesn't discharge.

In the nature of these things, there are a lot of variables, and you may get away with it. Using an old spark plug for the disconnected lead is just playing it safe.
I don't know how much the Excel amplifier costs, or if you can still get a new one. If you can't, its all the more worthwhile taking precautions.