Avensis 2004 Brakes - One Slider Pin Is Quite Stiff, Is This Ok?

[sferg]

Hi,

I am in the middle of fitting new front discs and pads to my 2004 T-Spirit D4D. I have noticed that one of the slider pins on the caliper assembly is quite stiff, and reluctant to push in to / pull out of it's cylinder. The other is a lot easier, more like I'd expect. The stiff pin has a grooved rubber bush towards the end of the pin, which appears to be causing the resisitance - the pin and cylinder are in good condition and I have lubricated them but this hasn't solved the problem...

Is this normal?! I'm concerned that the slider assembly is going to be unbalanced, and the portion of pad nearest the stiff pin will be less worn than the portion nearest the free pin. Either that or the assembly will seize up entirely and/ or the ABS & VSC wont be effective.

Any help / advice would be greatly appreciated!

Thanks in advance

Simon

[Fitter]

Hi,

I am in the middle of fitting new front discs and pads to my 2004 T-Spirit D4D. I have noticed that one of the slider pins on the caliper assembly is quite stiff, and reluctant to push in to / pull out of it's cylinder. The other is a lot easier, more like I'd expect. The stiff pin has a grooved rubber bush towards the end of the pin, which appears to be causing the resisitance - the pin and cylinder are in good condition and I have lubricated them but this hasn't solved the problem...

Is this normal?! I'm concerned that the slider assembly is going to be unbalanced, and the portion of pad nearest the stiff pin will be less worn than the portion nearest the free pin. Either that or the assembly will seize up entirely and/ or the ABS & VSC wont be effective.

Any help / advice would be greatly appreciated!

Thanks in advance

Simon

Both slider pins should be equally free but not slack and the rubber thing is a Dust Boot which should be replaced. If one pin is tight in the bush rub it down with some emery cloth until it slides freely.

Fitter

[sferg]

Hi Fitter, thanks for the reply. The rubber component is on the end of the pin and is termed a "bush" in the toyota manual, it goes in to the slider pin cylinder. It is only present on one slider pin. It seems to bind up if I leave it for half an hour or so, then it will free up with moderate force, only to bind up again if i leave it again for another half hour or so. The cylinder wall is as smooth as I'd expect it to be, although not a mirror finish. Any ideas?? Is this an anti-rattle bush?

Simon

[Jamesbelfast]

Whatwas the bush lubricated with.

Only special lubricants should be used as ordinary lubes will cause the bush to swell - hebce higer resistance.:)

[Fitter]

Hi Fitter, thanks for the reply. The rubber component is on the end of the pin and is termed a "bush" in the toyota manual, it goes in to the slider pin cylinder. It is only present on one slider pin. It seems to bind up if I leave it for half an hour or so, then it will free up with moderate force, only to bind up again if i leave it again for another half hour or so. The cylinder wall is as smooth as I'd expect it to be, although not a mirror finish. Any ideas?? Is this an anti-rattle bush?

Simon

There is only a bush on one pin and should be lubricated with Lithium soap base grease but both should have a rubber dust boot.

Fitter

[Thermal]

Hi,

As a picture says more than a 1000 words...

Here's the picture.

Note, that the upper and lower slider pins have a different shape, and only the bottom one has the slide bush, which is a non-reusable part.

Lubricate as Fitter said.

[sferg]

Thanks for all the replies.

I had thought that the grease I used may have caused swelling, however the bush appears to be original size and shape, e.g. it isn't loose on the pin or too large for the cylinder. However it is definitely this bush which is causing the problem, and I suspect that over half hour or so grease seeps into the grooves of the bush, causing a vacuum in the cylinder when I try and pull the pin out. Perhaps a new bush will resolve the issue.

Maybe the grease I have used is too fluid, and I need a "stiffer" grease to prevent it seeping down the grooves over time.

The grease I used was a high temp lithium based grease, no mention of mineral on the tub, so I thought it was suitable. It was translucent yellow /brown (like standard grease), not the white lithium I have previously used on bike bearings.

Any thoughts?!?

Cheers

Simon

[Jamesbelfast]

Mineral oil or lithioum based lubricants should not be used anywhere near rubber or plastics - it eventually rots them or makes them brittle.

A silicon based grease is best.:)

[Thermal]

The Toyota repair manual states: "lithium soap base glycol grease".

In my previous post I mentioned, that the slide bush is designated as a "Non-reusable Part".

That is, it must be discarded and replaced with a new part.

It may well be the source of your problem. ;)

[Q.S.]

Thanks for all the replies.

I had thought that the grease I used may have caused swelling, however the bush appears to be original size and shape, e.g. it isn't loose on the pin or too large for the cylinder. However it is definitely this bush which is causing the problem, and I suspect that over half hour or so grease seeps into the grooves of the bush, causing a vacuum in the cylinder when I try and pull the pin out. Perhaps a new bush will resolve the issue.

Maybe the grease I have used is too fluid, and I need a "stiffer" grease to prevent it seeping down the grooves over time.

The grease I used was a high temp lithium based grease, no mention of mineral on the tub, so I thought it was suitable. It was translucent yellow /brown (like standard grease), not the white lithium I have previously used on bike bearings.

Any thoughts?!?

Cheers

Simon

Fit a new bush and lubricate with the correct grease. If you can't get hold of that, use rubberlube. Sounds to me like the bush has been contaminated with an incorrect lube and has swollen slightly and gone 'grippy'. Was a common fault on the old vauxhall slider rubbers which used a silicon based grease but often got the wrong grease from DIY'ers and some mechanics.