Oh crap, I've broken it!!!!!

[Bannedbiker]

Had a couple of tyres fitted today. As I handed the keys over I thought I'd better remind them about the suspension on a Xantia and the need to put it in "high" before raising on the ramp.
"No problem" was the answer as he took the keys out to the chap who was to fit the tyres.
It was only as the car started to go up in the air that I realised they hadn't raised it. Can't do any real harm I thought though.
Got the car home no problem (only a couple of miles) and jacked the car up to swap the wheels front to rear as the new tyres were put on the back wheels. I raised the suspension before jacking the car up.
When done I lowered the suspension to normal, the front lowered first as usual then dropped to the floor, then fully raised again. Oh bugger!!! The dogleg must have popped off
The rear went to the correct height but the front continued to swap between high and low. Great timing, I've got to drive to London tomorrow. Double bugger!!!
Got the car ramps out and drove up them in "high". With axle stands in place I checked the dogleg, it was still attached.
So I drove off the ramps again and with the suspension on low undid the bleed screw.
Did a couple of rounds of "citrobics" and car's ok again.
Must have been an airlock in the system from being raised in normal earlier.
Needed to have a sit down and a cup of tea afterwards, really thought the car was buggered for a while.

Martin.

[Mandrake]

The garage jacking the car up without raising the suspension won't do it or the suspension any harm, the only problem is that when they lower the jack they may not be able to get the jack low enough to remove it until the engine is run allowing the car to lift back up to normal height again. (If they don't know about this it will cause a few puzzled looks though! )

Sounds like all that happened when you swapped the wheels is that you lowered the suspension from full to normal when there was sideways thrust on the suspension. If you have the suspension at full height and jack the car up off the ground completely to change wheels, when you lower the car back onto the ground and then drop the suspension to normal height the geometry of the front suspension causes the wheel track to change width, which puts a lot of sideways thrust on the front suspension rams, causing a lot of extra drag/friction in suspension movement.

This then causes the height corrector to keep overshooting - it will drop down too low, then spring back up too high, then drop and so on. It would keep doing it indefinitely if you left it, and this is perfectly expected behaviour as a side effect of the suspension geometry.

The solution is simple - as you are lowering the suspension from full height to normal height after having lifted the wheels right off the ground simply let the car roll slowly backwards or forwards until the height has reached normal, this will release the sideways thrust on the suspension as it moves and allow the height to stabilise normally.

Nothing to do with air locks, and nothing to worry about.

[DHallworth]

It's actually advisable these days to leave new tyres on the back of the car for a couple of reasons...

It means that you will wear the tread down on the back tyres meaning that they'll wear rather then just get old and perish on the rear. It also means there's less chance of the back of the car stepping out during cornering in the wet.

Less of an issue on rear wheel drive cars as the rear tyres are usually bigger but they wear anyway due to the drive being there.

http://www.popularmechanics.com/cars/how-to/4243992

http://www.youtube.com/watch?v=whHbWYmxpwg

Personally I'd of left em where they were.

David.

[Northern_Mike]

It's actually advisable these days to leave new tyres on the back of the car for a couple of reasons...

It means that you will wear the tread down on the back tyres meaning that they'll wear rather then just get old and perish on the rear. It also means there's less chance of the back of the car stepping out during cornering in the wet.

David.

So, you slither nose-first off the road when your tyres that are steering lose grip, rather than crash backwards through a hedge?

I've read this piece of "advice" repeatedly over the years, and can only surmise that it's for people that can't drive and have absolutely no clue about driving dynamics. I *always* have the new tyres on the front - it does the most of the braking and all of the steering. It's never, ever caused me a problem in 23 years of driving. Personally, I think that if your rear tyres are that worn that they lose grip in the wet and you crash, it's your own fault as they're worn enough for you to have changed them before you crashed..

[Bannedbiker]

I've never had it happen before in the 3 years I've owned the car, lost count of the times I've had the car jacked up over that time.
I had actually rolled it back before driving up the ramps to check the dogbone and it was still nodding up and down before I put it in "high".

And the reason I wanted the old tyres on the rear was that they were budget tyres and the new ones were a better make. I've never had an issue with grip at the rear, the only time I've found a problem was on a wet roundabout the Xantia's front wheels did understeer with cheap tyres.

[Mandrake]

It's a bit of a controversial topic really, I think it matters what is wrong with the rear tyres - are they just low on tread but otherwise good, is the tread depth fine, but the rubber is getting old and perished ? Are they a different, inferior brand/type than the ones that are going onto the front etc ?

Traditionally I've always put new tyres on the front and transferred the front tyres to the rear while they are somewhat worn but still have plenty (at least half) of their tread depth left. This way the front tyres which do all the steering, power transfer, carry the most weight, and do most of the braking are in the best condition, whilst the rear tyres are kept at an acceptable age and rubber condition because half their wear was done on the front over a shorter period of time instead of taking years to wear to the same point on the rear alone. (I do agree that tyres only ever used on the rear wear too slowly thus the rubber perishes before the tread wears down..)

While having more grip at the rear might be good advice for some cars, and novice drivers, a very front heavy front wheel drive Citroen that tends to understeer is not going to become dangerously oversteery just because the front tyres have a bit better grip than the rear, if anything it will bias it more towards neutral handling.

When I changed my previous Xantia from 185/65/15 to 205/60/15 I did it two tyres at a time - I put the new larger tyres on the front and left the old ones on the rear for a few months. The new tyres had arguably much more grip than the rears (better quality tyres as well as wider) yet I had no problems with oversteer or the rear running wide even in the wet.

The only time you'll run into problems with the front tyres being better than the rear on a Citroen is if the rears are completely substandard - no tread left, or the rubber is hard and perished due to age, in which case the tyres should have been replaced and definitely aren't suitable for the front either.

If you're trying to get traction in snow/ice conditions you definitely need the best grip on the front or you won't be going anywhere at all....

[Bannedbiker]

The old tyres I've put to the rear were a "Ceat" that had only done about 500miles (was the spare tyre until a couple of weeks ago) and an Admiral with 5-6mm of tread. Neither tyre is a make I'd choose if buying tyres but were what was on the car.
As the Xantia is nose heavy I would rather have the better tyres at the front. With my Mx5 I'd put the better tyres at the back as it's rear wheel drive.
Anyway, just glad the car is ok.
Moral of the story, don't bugger about with the car if you need it for a long journey the next day.
I am a plum!!!

[Northern_Mike]

I had good tyres all round on my first MX5. I still binned it.

[Bannedbiker]

I've got Falken ZE912's on mine and they've been brilliant, only time I've lost grip is on standing water while braking hard.
In fact I was so impressed with them that they are what I had fitted to the Xantia today.

How badly did you bin it?

[Old-Guy]

As far as I'm concerned, it's a no brainer:
The front tyres on a Xantia wear 2-3 times faster than the rears confirming that they do most of the work - if they lose grip you can't stop, go, or steer. If the rears lose grip you apply opposite lock and give it a bit of welly. A tail-happy rear-drive car can be hugely entertaining - a front-drive understeering pig ends up in the scenery before too long.
Like other contributors, my new tyres always go on the front; fortunately as I fit my own, I don't have arguments with ignorant tyre-fitters who don't understand the importance of torquing wheel bolts/nuts correctly instead of torquing them and then swinging on a big bar. Rant over!

[Bannedbiker]

I don't have arguments with ignorant tyre-fitters who don't understand the importance of torquing wheel bolts/nuts correctly instead of torquing them and then swinging on a big bar. Rant over!

That's one of the reasons I wanted to swap them over myself. They had done the tracking so wanted to make sure everything was ok there and always re-torque wheels myself so I know they will come undone at the side of the road if I get a puncture.

Although there are some good people in these tyre places there are also so people I wouldn't let loose with a tin opener let alone allowing them to work on a motor vehicle.

[Northern_Mike]

I've got Falken ZE912's on mine and they've been brilliant, only time I've lost grip is on standing water while braking hard.
In fact I was so impressed with them that they are what I had fitted to the Xantia today.

How badly did you bin it?

It was a Eunos with non-standard suspension and was quite erm, firm. I had Pirelli P6000s on it. Powering round a bend - a bend I'd driven, quite literally, over 2000 times before,in other cars, in the rain, there is a bump mid-corner. It was the first time I'd driven round it in the Eunos. Doing about 55-60 with my foot on down in 4th, it hit the bump and just went sideways, not even a hint of a slide. One second I was going round the bend, the next I was sliding down the road pointing at 90 degrees into to the direction of travel. Narrowly missed a poor woman in an Audi A4 coming the other way, then the nose of the car dug into the grass banking, flipping me up so high up on the side that the drivers door mirror and door handle had grass on them. At this point I ducked, but the car landed shiny side up and ended up pointing the wrong way back on the road, bent bonnet and wing, both drivers side suspsension bent and with flat tyres, the exhaust lying about 50 yards up the road and various bits of the underside missing. Being a wannabee rally driver, the first thing I did was reach for the key, restart the engine, and drive 200 yards down the road to a safe place, rather than be sat on the exit of a bend. The poor woman who I'd narrowly missed had actually turned round and come back to see if I was ok - she thought I'd gone off the other side off the road, a 20ft drop into a field. Some git in a transit came past and drove over my exhaust and continued with it trapped under him until he was out of sight!

I was ok, had a bump on my head and was a bit stiff for a few days. The next Eunos I had had the same suspension set up, but Avons on it, and was fantastic wet or dry..

[Northern_Mike]

I don't have arguments with ignorant tyre-fitters who don't understand the importance of torquing wheel bolts/nuts correctly instead of torquing them and then swinging on a big bar. Rant over!

That's one of the reasons I wanted to swap them over myself. They had done the tracking so wanted to make sure everything was ok there and always re-torque wheels myself so I know they will come undone at the side of the road if I get a puncture.

Although there are some good people in these tyre places there are also so people I wouldn't let loose with a tin opener let alone allowing them to work on a motor vehicle.

The little place I use is brilliant. Family run place, always do what you ask, know what they are doing and are cheaper then mytyres or blackcircles, even with fitting..

[Bannedbiker]

I've got Falken ZE912's on mine and they've been brilliant, only time I've lost grip is on standing water while braking hard.
In fact I was so impressed with them that they are what I had fitted to the Xantia today.

How badly did you bin it?

It was a Eunos with non-standard suspension and was quite erm, firm. I had Pirelli P6000s on it. Powering round a bend - a bend I'd driven, quite literally, over 2000 times before,in other cars, in the rain, there is a bump mid-corner. It was the first time I'd driven round it in the Eunos. Doing about 55-60 with my foot on down in 4th, it hit the bump and just went sideways, not even a hint of a slide. One second I was going round the bend, the next I was sliding down the road pointing at 90 degrees into to the direction of travel. Narrowly missed a poor woman in an Audi A4 coming the other way, then the nose of the car dug into the grass banking, flipping me up so high up on the side that the drivers door mirror and door handle had grass on them. At this point I ducked, but the car landed shiny side up and ended up pointing the wrong way back on the road, bent bonnet and wing, both drivers side suspsension bent and with flat tyres, the exhaust lying about 50 yards up the road and various bits of the underside missing. Being a wannabee rally driver, the first thing I did was reach for the key, restart the engine, and drive 200 yards down the road to a safe place, rather than be sat on the exit of a bend. The poor woman who I'd narrowly missed had actually turned round and come back to see if I was ok - she thought I'd gone off the other side off the road, a 20ft drop into a field. Some git in a transit came past and drove over my exhaust and continued with it trapped under him until he was out of sight!

I was ok, had a bump on my head and was a bit stiff for a few days. The next Eunos I had had the same suspension set up, but Avons on it, and was fantastic wet or dry..

Mine's an Eunos too, 1997 1.8 litre. I found the standard suspension too stiff so fitted standard units from a 1999 Mk2 Mx5. I found that along with being a bit more comfy (still no limo, it's a sports car after all ) it allowed the wheels to follow little bumps rather than skip over them. Doesn't roll anymore in bends either.

On an old Suzuki GSXR 750 I had some years ago someone thought it would handle better if they stiffened the suspension fully up as far as the settings would allow. It was great in a straight line but show it a corner and it didn't want to know. Made my bottom go like a rabbits nose a few times, I can tell you!!!!

I take it you don't still have your 2nd Eunos then Mike?

[Bannedbiker]

I don't have arguments with ignorant tyre-fitters who don't understand the importance of torquing wheel bolts/nuts correctly instead of torquing them and then swinging on a big bar. Rant over!

That's one of the reasons I wanted to swap them over myself. They had done the tracking so wanted to make sure everything was ok there and always re-torque wheels myself so I know they will come undone at the side of the road if I get a puncture.

Although there are some good people in these tyre places there are also so people I wouldn't let loose with a tin opener let alone allowing them to work on a motor vehicle.

The little place I use is brilliant. Family run place, always do what you ask, know what they are doing and are cheaper then mytyres or blackcircles, even with fitting..

Just remembered, after the car was lifted up on the ramp they decided to remove the spare wheel from it's carrier (it was one of the wheels that needed a new tyre). I did wonder why the chap was emptying the boot as the lowering bolt is right at the back, accessible with all the gear still in the car.

It was when I saw what looked like a tug at the rear edge of the carpet that I realised the silly sod was trying the lift the carpet, either to see the lowering bolt or to get at the spare wheel (I didn't ask).

I ran out and pointed out the location of the bolt and left them too it (head in hands).