Adjusting handbrake on a 120.

[Crispin]

So my mention of adjusting the nut in the cable received rolling eyes from people. I want to do it properly now. Rob mentioned something about a hole in the rear calliper were I should do something.

I slackened off the nut this evening and it's pretty clear that one seems to grab before the other. The spreader bar pulls to the side when applying the brake.

Finally, could this have been the cause of me tightening up the nut: When I stomp on the brakes, the back lurches to the side. Front is fine but the back is not happy. As I've said, I have slackened off the nut (because I was told to) so will see tomorrow but could it have been the reason for this pulling? I've never felt it before today.

 

[Chris]

Before anyone launches a rescue attempt on this one, I covered the whole procedure on the 90 section somewhere, in detail. Hand brake is exactly the same. I'll have a quick look and be back in a mo.

C

Oh yes, here look. Try that. The secret is in the little cog.

viewtopic.php?f=14&t=260

 

[Crispin]

Thanks. If they are the same then I'll follow your many threads on the subject

 

[Paul]

Thought you had servicing by Mr. T?

 

[Crispin]

Thought you had servicing by Mr. T?

Let's not go there shall we?
A rather large cockup that has turned out to be. Costly too....

 

[Jon Wildsmith]

When I stomp on the brakes, the back lurches to the side. Front is fine but the back is not happy.

Most likely cause is stiff or siezed slide pins on the rear brake caliper on the side it lurches away from. It could be a siezed piston but the slide pins cause trouble more often especialy if some joker put the wrong grease on them in the past

 

[Rob]

especialy if some joker put the wrong grease on them in the past

what's the correct grease to use then?

 

[Chris]

The rear brakes are not an especially good design. There is a rubber tube into which a large pin slides. This keep the slider parallel. If you put the WRONG grease in there, usually copper anti seize then it hardens and stop the pin from sliding. I have not used red rubber grease but I would think that that would work well, or even CV grease which remains mobile and soft. I have to confess that I don't know the correct spec, but I have seen plenty that have been over greased and gone solid. I would advocate using only a little of what ever you put in. Just enough to be able to slide the pin in on initial assembly.

My experience of Toyota brakes (and I have had a lot of Toyotas) is that they have never been a really good design what ever the car. Maybe that is the same for all manufacturers, but having had Toyotas since I was in my teens and very little else that I have worked on myself. Maybe T brakes are the best in the World and others are shocking. But, having driven many makes, I would also say that I have never been impressed by Toyota brakes either.

Bit surprised that you get such a response under hard braking from a poor rear brake. Most likely that it is a slide pin as Jon said and probably only one pot is working making it yaw in the caliper. Be very careful with the little rubber tubes, they tear very easily. Better to have a spare on standby before removing them. To get them in, grease them on the outside, fold them longways and slide them through the caliper.

Best medicine for Toyota brakes in my opinion is regular movement and maintenance. Remove a pad every 6 months and push the piston out a bit, loosen the nipple and push it back in again. Keeps the fluid fresh and the seals moving. Same with handbrake. Keep the bellcrank moving.


Chris

 

[Jon Wildsmith]

what's the correct grease to use then?

A grease that says it's suitable for use with rubber - usually vegetable based and red but there may be others. Copperease reacts with the rubber and first makes it gooey and then dries out and locks everything in place.

 

[Crispin]

[quote="Crispin":3prqlzr3]When I stomp on the brakes, the back lurches to the side. Front is fine but the back is not happy.

Most likely cause is stiff or siezed slide pins on the rear brake caliper on the side it lurches away from. It could be a siezed piston but the slide pins cause trouble more often especialy if some joker put the wrong grease on them in the past [/quote:3prqlzr3]


mkay, with a mildly severe hangover I had a look at this. I'll save you the comical screwups that took place.

Both rear calipers are fine. All rubber bits are good and rubbery with no tears. Slidy pins on the right were without grease but were free. The left caliper was also fine but these pins had white grease on them.

I don't know how thick a new pad is but these had about 4-5mm left one them so not dead but nearing it. I'll replace them next weekend.

Both pistons move freely in and out. In fact, so free that I popped one out. I was not to pleased with myself.
After much faffing to remove the caliper and get the rubber seals in place I put it back on. I bled it by undoing the bleed screw and pumping the pedal once or twice before brake fluid came out.
The brakes still feel spongy though. Is there something else I need to do? While I was messing with the caliper I let the brakeline drip into a pint glass. after a few hours (baby duty, football match and hangover nap) I had collected about half a pint on fluid. I just put this back into the tank.
Do I need to bleed more for the spongyness?

CP

 

[Chris]

Too late tonight for a full reply. But number one. Don't re use brake fluid. Chuck it. It is hygroscopic - it absorbs moisture. That is not a good thing to have in your brake lines. You need to bleed you brakes properly. Letting them drip through is not bleeding.

Off to bed for now. How's the dog guard?

Chris

 

[Crispin]

well that sucks then....

The "dripping through" was not in way of bleeding. It was while the caliper was disconnected and I did not seal the pipe. I figured I would just let it drip into a clean glass and reuse it.

 

[TonyP]

Give me a shout tomorrow and I'll come and help you bleed them. It's easier with two people doing it, and hopefully there wont be any alcohol to impair you

 

[Nuclear Chicken]

Yes bleed tham with 2 people. The system is servo pumped and needs the ignition on to keep fluid pressure. If your fluid is 'old', i.e. more than 2 or 3 years, then it is worth a complete change if you can manage that. Get some Toyo DOT5. And yes it is fully back compatible with older fluids.

Oh and yes, Chris is bang on the money. Never reuse fluid. EVER. Doen't matter how clean your jamjar is. EVER.

 

[Crispin]

Thanks fellas. I've ordered new pads all round and will change them tomorrow.

Seeing as I am now on the min mark in the reservoir, I'll buy some more and change it. Can I just loosen the nipples and pump until it's empty and then fill up and bleed them? Anything special with the ABS?

 

[Chris]

No need. Bleed it through with plenty. The new fluid can't really get past the old fluid in the lines. If you empty it out, you'll just end up with even more air in there. I like to set my pistons right back into the cylinders before I bleed so that there is less air space in the caliper and nowhere for water or anything to hide. As you will be opening the bleed nipples one at a time, fluid will find the easy route out, especially if you have new pads in of course so you won't be bleeding much at all. Just the lines basically and the LSV which has its own bleed nipple.
Keep checking that level though it drops pretty quickly and then suddenly you are right back at the start.

Chris

 

[TonyP]

Keep checking that level though it drops pretty quickly and then suddenly you are right back at the start.

been there and done that one before.....

 

[Rob]

Keep checking that level though it drops pretty quickly and then suddenly you are right back at the start.

been there and done that one before.....

ditto

 

[Chris]

OK OK , me too. But only ever once. Or maybe err, damn you guys. OK more than once, maybe.

C

 

[Crispin]

Get some Toyo DOT5. And yes it is fully back compatible with older fluids.

Dumb question: Book says DOT3. From what I can see, the only difference is the boiling point (thanks to wikipedia:http://en.wikipedia.org/wiki/Brake_fluid)

Dry boiling point Wet boiling point
DOT 3 205 °C (401 °F) 140 °C (284 °F)
DOT 4 230 °C (446 °F) 155 °C (311 °F)
DOT 5 260 °C (500 °F) 180 °C (356 °F)
DOT 5.1 270 °C (518 °F) 190 °C (374 °F)

So long as you go higher up, you safe? No other difference?

edit:
I read on. Dot 5 is silicone based and hydrophobic. has a few other properties to boot.

NC - what makes you say it's backwards compatible?

DOT 5 is silicone fluid and the above does not apply. Ideally, silicone fluid should be used only to fill non-ABS systems that have not been previously filled with glycol based fluid.

Granted, the above is from wikipedia and is someones opinion

Cheers,
CP