Brake caliper screws & wheel bearings

[pretzelz]

Hi,

I'm trying to do some basic DIY with my car, so I might make this forum a regular visit At the moment, since I'm trying to replace the brake pads, rotor and bearing on a wheel - I'm at the first point of actually trying to unscrew the brake calliper. I've found the correct socket size bit for my wrench, jacked up the car and have it on a stand, but even with some heft force, those break caliper screws are not coming off.

How much pressure can I apply here? Should I bang at my wrench handle with a hammer? Or spray some WD40 on the screws? ...The wheel itself was a pain to get off, I had to drive it round the block with the lug nuts loose just to free it up!

Many thanks! (it's an '98 Daihatsu Cuore 850cc)

 

[Stivino]

My advice would be to only use a good fitting six-point socket because you don't want to round the caliper bolts. When the socket turns, you want the bolt to move with it. It shouldn't be too tight so a moderate amount of torque should make it go. I wouldn't give it a sharp dunt, instead I'd gently apply pressure and increase it until it goes.

 

[pretzelz]

Thanks Stivino, i'll apply some stready pressure tomorrow and hope for the best : )

 

[pretzelz]

- Actually, just before I go and make a muppet of myself, how about this idea...

I have an impact wrench, I'm not sure what size it is but it works with a particular socket on my wheel's lug nuts. Anyway, if I buy an impact reducer set http://www.toolsandleisure.co.uk/3pc-impact-reducer-set-285-p.asp - something like that I imagine, then is it feasible to use an impact wrench on a rusted nut to get it off? Or will it just tear the head off the nut?

 

[xerxes]

You can use an impact wrench, and you must use an impact socket with it (these normally have a black phosphated finish). Get sockets to suit the drive size of your wrench (half inch?) and avoid using a reducer. An impact socket will be a simple hex fit, as Stivino advises you to use, rather than a bi-hex which brings the danger of rounding off the corners. Try to clean up the heads as well as possible and make sure the socket sits over the head snugly before you begin.

Alternatively, get a good breaker bar (about two feet long of a half-inch drive) as this will give you a lot more torque than a short bar or a ratchet.

If you have any access to get some penetrating oil into the threads before you begin, give it a good soaking.

 

[pretzelz]

Thanks for the guidence.

I'm in the process of aquiring some necessary tools... with regards to doing the wheel bearing, this is the list of tools that a page told me about:

# Large adjustable wrench and Channelocks.
# Bearing race driver tool or various size punches.
# Socket and ratchet set or assorted wrenches.
# BFH.
# Lots of rags.
# New wheel bearings.
# Wheel bearing grease.
# New cotter pin.
# New grease seals.
# Wheel blocks.
# Safety glasses.
# A jack and a pair of jack stands.
# Rubber gloves (Optional)

The new wheel bearing I bought for my car obviously doesn't come with a cotter pin or grease. I can find wheel bearing grease on ebay, but:

- is there a certain size cotter pin I should order?
- And what is a grease seal?
- Also is there a particular size channel lock and race driver tool I should be looking for?
- And is BFH a brute force hammer? Is this just a regular hammer, we have a few sizes from small to big at home.

Many thanks, it's a fun learning curve!

 

[Stivino]

Usually when you get a wheel bearing kit, it comes with a new pin, seal and grease. Just get a pin the same size as the one that comes out, they're usually 3 or 4mm ish.
Channelock to me is a brand name so it could mean any number of things.
And to me a BFH is an FBH (Fkn big hammer)
Got the caliper off yet?

 

[JohnD]

rubber gloves fall apart when they get oil on them.

buy neoprene gloves which are thin and have good feel and grip.

 

[xerxes]

Not to overload you with more gratuitous advice, but ...

Photocopy the relevant page(s) of the manual before you begin. It will get greasy if you refer to it a lot when you're doing a job for the first time. When you finished, jot down any experience notes (hints to yourself for next time, problems you've solved) in the manual so that next time you do the job, it will be a bit easier.

Get a magnetic tray (large rectangular one is best) and arrange the small parts in it as you dismantle them. Not only can this save you losing vital bits, it can help a lot when you're reassembling something unfamiliar.

I use disposable nitrile gloves, which are fairly tough but allow good feel. Any time you need to, you can tear them off and you've instantly got clean hands.

 

[JohnD]

oh yes

I might have meant nitrile

The blue ones, yes?

 

[xerxes]

The blue ones, yes.

Or if you want a part in the Bill, make sure you get the purple ones.

I've just bought 300 nitrile gloves from Ebay, size XL. Sadly, I find that that particular make has a range that goes up to XXL; the XL size is a bit on the small side. Things could be a bit tight over the next year or so.

 

[pretzelz]

Thanks everyone for your advice, it's great to be able to turn to a forum when you're off on a new adventure that has pot holes all along the way.

I'll be embarking on the calliper tomorrow (wednesday) but wanted to accumulate the necessary tools together first, as I expect that just replacing the brake disc and pads will not be full sufficient so long as I've still got a bad bearing. I suspect the bearing is bad because I can take hold of the wheel (lugged-in) and rock it slightly, which was pointed out to be the cause of a bad bearing in a video on youtube... apparently.

Honestly - my car was making such a LOUD grinding noise that people passing in the streets would all stop and stare, it was hideous. Now that I've got the wheel off and can see the brake disk, it's really rusted, and there is a big grazed rust patch that I think must have been making the once-a-rotation grinding noise. ...I imagine putting this shiney new brake disc and pads (not that the current pads look worn thin) will get rid of that aweful noise. But I guess the bearing will have to be replaced to avoid corrupting the new parts I'll be putting in.

On a side note, all american references I see to the cost of such wheel parts seem about 1/4 cheaper than what we have to pay for here. For instance someone quoted that a wheel bearing should cost about $15-$25. Try £37. ($60)

 

[xerxes]

The price differential has something to do with large-scale, efficient industry on the other side of the Atlantic, I believe. And they're not burdened with penal taxation or an overmighty European Union to add to the costs of doing business.

I'm not sure from what you say whether it's a worn-out brake pad that's making all the noise, or if the wheel bearing is noisy too.

Missing from your list is a tool for extracting the old pads, and a tool for compressing the caliper pistons in order to fit the new, full thickness pads. You may be able to improvise in both cases, with levers and screwdrivers.

You are planning, I hope, to do the brakes on both sides of your vehicle? Pads, and discs (rotors) should be replaced at both ends of an 'axle' to make sure that braking remains balanced.

 

[pretzelz]

hmm, well, i'll be honest with you... I was planning on this being my first ever test foray into the world of DIY auto mechanics, so I decided to get only the parts for one wheel (although it came with 4 break pads for all wheels at least) ... and see if I had success doing one wheel, then evaluate doing the others myself, or take it to a garage and have them doing it. But ultimately I want to become self sufficient with the basics.

I'll be following the DIY auto guides on about.com which is where I got the list of tools from. They recommended to use a c-clamp to push the piston back to insert the new brake pad. Pad or pads? If it's pads, then I guess I'll only be covering 2 wheels, not four. I bought 4 brake pads for £30 + vat from a mainstream supplier, branch in Southampton.

Tonight I went hunting for various tools in B&Q, then the Range. I skipped Halfords and Wickes, since Halfords is always too expensive and Wickes website didn't even list the parts I was looking for. To look at the caliper Wednesday/Thursday and practice removing the disc rotor and brake pads, I'll still need a c-clamp, bungee cord and dead blow hammer. I'm not confident I'll find them within two days, so I may only get the calliper on and off to nose about, then reassemble that.

 

[pretzelz]

http://autorepair.about.com/od/fixityourself/ss/brakepadreplace.htm