sticking front brakes

[bonjo]

I noticed over the past few months the fuel consumption had got worse.

I also noticed the car would not free wheel and came to a halt as if the brakes were slightly on.

After a drive, the left wheels is much hotter than the right one. Externally, the disc looks ok so I am thinking maybe the brake calliper is sticking and needs servicing.

Any suggestions or recommendation?

Is there a calliper overhaul kit available?

thx
 

[Mark O]

I would say the caliper is indeed sticking. If you are lucky the caliper may simply be picking up on the guide pins, or the pad may picking up on the small metal guide/support plates. Remove them, dress them off, smear with silicon grease and replace. If you are unlucky, the brake piston itself could be picking up inside the caliper and not retracting. In this case, you may be able to push the piston out far enough to dress it off, grease and push back - do not pop it out though!. More likely a new caliper c/w brake piston etc is required. Plenty about on the web - send your old one in as exchange...brakeparts are usually pretty good.    

This link will illustrate 

http://forum.http://www.toyotaownersclub.com/forums/forum/79-rav-4-club//topic790.html

[bonjo]

thanks very much for the helpful info and the link.

hopefully it is case 1 or 2 as taking the piston out will probably mean new seals and fluid.

Do you think I should budget & replace the pads while the calliper is off? At last recent service 65k miles they had 6mm left on them

BTW what do you mean by "dressing"? also is "brakeparts" a supplier or you meant spares?

 

[Mark O]

There is no fundamental reason why you cannot remove the piston entirely, but as you say, you will require new seals and probably new dust covers if you do. There is no need for new fluid, but you will need to bleed it thoroughly after re-assembly. Keep everything clean.  My advised method has worked in the past for me, but dependent on just where the piston is picking up I cannot guarantee it works every time. Clearly there is no need for new seals or fluid or bleeding if the piston is not "popped" out.  However, If the piston or caliper is badly corroded, i would suggest replacement of the caliper c/w new piston and seals. Easy enough to fit.

Dressing off means abrading the metal  - in this case with emery cloth/wet and dry/flap wheel to remove all traces of surface corrosion.

Brakeparts are a supplier of reconditioned brake calipers, discs pads etc etc. Google is your friend

Pads - depends if they are worn down or not. If there is still plenty of pad abrasive material left, personally I would not replace them.

[Ant-Rav]

Have had this same problem on many many occasions. On both my rav,s and my last old avensis d4d. And only twice did I have to buy a reconditioned caliper. Mechanic always seemed to free up the piston or whatever was ceased. And even when I did replace the caliper, they always cease up again. Get ur mechanic to free it up, or at least try to. Pad nearest the piston inside the caliper could be well worn down by now possibly needing a change. I would try to put off buying caliper personally.

[Mark O]

I think you may find it is the other way around. The attempts at freeing up existing equipment can be successful, but as as you are not replacing worn parts such as seals, boots, pistons etc., the likelihood of the problem repeating itself is greater than if you replace the caliper with a reconditioned unit - which will have new seals/boot and possibly piston.

However, by simply freeing things up, that is not to say the problem will necessarily reappear soon - just probably sooner than if you replaced the caliper.       

[bonjo]

thanks for all the useful info.

from my little previous experience, it has usually been the movement of the pads being restricted as mark described. So I hope this is the case.

I'll start with this and move onto replacing the calliper depending on the outcome.

BTW should you replace both side callipers together or just doing one is ok? And should I get toyota branded spares or alternative brands?

thanks once again

 

[Mark O]

Personally I would remove the pads, caliper and dust boot. Pump the piston out further - but do not pop it out of the caliper! - remove any corrosion, clean the surface of the piston up, grease and push back in. Remove the guide pins and the pad seats - the small metal tangs on the carrier - remove any corrosion, clean them up,  grease and replace. Essentially ensure the pads are free to move when in operation.

If things are badly corroded, then replace the caliper. Dependent on price, i would be tempted simply to replace the caliper in the first instance.

I don't believe there is any requirement to do both calipers - the brake force to each caliper evens itself out, though the braking force to the wheel itself may be different - due to differing pads, tyre, bearings etc etc. Unless you also equalize all of these, there is little point in doing both calipers.

Spares - Toyota parts for low cost stuff such as seals etc if required. Pads - personally I use Mintex - as good as anything else - 35 quid per set IIRC.

One other point- the link mentions shims to avoid brake rattle/squeal. On disassembly, mine did not have any, and I did not bother installing any. Lots of coppergrease on the back of he pads though. I read somewhere that new pads do away with the need for shims.    

[bonjo]

thanks pal very good fine details. I have a probe around when I get back from my forthcoming trip (if the weather is not hostile!).

It's been a long time since I last got down on my knees to this level but with the soaring garage costs and poor workmanship I really have to start doing what I can myself if it is cost effective and within my abilities.

your point about not necessarily needing both callipers, makes sense.

 

[Mark O]

There is plenty to be said for DIY. Firstly it does indeed save a stack of money, you can do the job when you want to, and you learn how your car works along the way. Forums like this and the internet in general are full of advice - though admittedly you have to sort the wheat from the chaff at times. Manuals of course are always a help. A cheap Haynes from eBay or similar will usually assist matters. 

Take your time, read as much as you can about the job, use decent metric tools - spanner and socket set is all you really need for this job, plus a torque wrench at a push - and do not be frightened of having a go.

[bonjo]

I used to do that quite a lot until a good few years back, but then with the non stop addition of engine management electronics, the cost of sensors and tooling, I gradually stopped.

I was also able to rely on competent dealers for the  cars and their prices was not astronomical. Having said that some their all inclusive service offers are good but you are still taking a risk with the workmanship!

So here we are today. I guess this is called "progress".

[Mark O]

I believe it is called technology - which should not be confused with progress. One reason being your first sentence.....

I also own a 73 MG Midget. I am not a mechanic, but given the right tools, there is practically nothing on it that I cannot fix myself.

[PaxosStu]

Just had the same problem with mine. Bought a caliper service kit from German firm on eBay & all sorted now

http://www.ebay.co.uk/itm/182056913468?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

 

[bonjo]

Up date on this

in the end I went to an independent garage as I don't have enough flat space to do the work and I didn't know how long it would take me.

The price went down from 310 to 180 (including the reconditioned part

Since the change (3 months ago), the fuel consumption has improved by 10~15%. In fact taking into account I no longer live in rural area and with ethanol in petrol, the improvement is even better!

The car free wheels much better and when stationary, I have to use the hanbrake a lot more often.