02/1.0gs Yaris Spongy Brake Pedal

[kman1]

I have been using the mrs's yaris (1.0GS 2002 40k) for the last couple of days. I noticed a couple of times that during firm braking the pedal felt soft and dropped another inch or so when I was expecting it to hold firm, which isn't right.

Brake fluid level ok, no obvious leaks, pads ok and no recent work completed no warning lights.

What other checks can I perform to try and identify the cause? Is master cylinder failure common on these?

[Raeman]

I have been using the mrs's yaris (1.0GS 2002 40k) for the last couple of days. I noticed a couple of times that during firm braking the pedal felt soft and dropped another inch or so when I was expecting it to hold firm, which isn't right.

Brake fluid level ok, no obvious leaks, pads ok and no recent work completed no warning lights.

What other checks can I perform to try and identify the cause? Is master cylinder failure common on these?

Hi mate, as far as i'm aware, the master cylinder is not a common failure on Yaris. That's not to say it can't fail of course.

Sounds like there's air in the system, has the fluid been changed correctly? is the fluid dirty?

Could be air in the system, only way to check is to bleed it.

Good luck. ;)

[kman1]

I have been using the mrs's yaris (1.0GS 2002 40k) for the last couple of days. I noticed a couple of times that during firm braking the pedal felt soft and dropped another inch or so when I was expecting it to hold firm, which isn't right.

Brake fluid level ok, no obvious leaks, pads ok and no recent work completed no warning lights.

What other checks can I perform to try and identify the cause? Is master cylinder failure common on these?

Hi mate, as far as i'm aware, the master cylinder is not a common failure on Yaris. That's not to say it can't fail of course.

Sounds like there's air in the system, has the fluid been changed correctly? is the fluid dirty?

Could be air in the system, only way to check is to bleed it.

Good luck. ;)

I don't think the fluid has ever been changed on this car, looks like a vegatble oil colour. The spongy pedal is a recent thing, previously it used to feel very firm.

[Raeman]

Wouldn't do any harm to change the fluid if it's never been changed since the car was new.

You could check around the master cylinder for any leaks or any loose pipes ect, also have a look under the car and examine the brake pipes and callipers.

If all looks ok, then i would take it to a decent garage and have it checked over.

Have you checked the rear brakes? The master cylinders in the rear drums may have burst or be leaking. You will have to remove the drum cover though for this check.

Good luck, keep us posted. ;)

[T V O R]

I don't think the fluid has ever been changed on this car,

There's your answer!

Brake fluid should be every 2 years. It absorbs water over time reducing its effectiveness, the water brings down the normal boiling point of the brake fluid and air bubbles are created as a result. The braking system will appear completely normal until the brake fluid reaches the reduced boiling point - which usually occurs after braking heavily.

What happens next is this: the brakes take on a sponge-like feeling and don't work - so the car fails to stop. If this happens on a hill or driving along a motorway, you are stuffed

Get it changed ASAP, it could save your life

[kman1]

I don't think the fluid has ever been changed on this car,

There's your answer!

Brake fluid should be every 2 years. It absorbs water over time reducing its effectiveness, the water brings down the normal boiling point of the brake fluid and air bubbles are created as a result. The braking system will appear completely normal until the brake fluid reaches the reduced boiling point - which usually occurs after braking heavily.

What happens next is this: the brakes take on a sponge-like feeling and don't work - so the car fails to stop. If this happens on a hill or driving along a motorway, you are stuffed

Get it changed ASAP, it could save your life

Done the fluid change, flushed about 1/2 litre through. Taken it for a test drive, I'd say the pedal travel is the same but they do seem to bite harder; can lock the wheels ok.

I wanted to inspect the rear brakes but I couldn't get the drums off. I take it the best way is to screw in a couple of bolts in the threaded holes to persuade em off, any ideas about what size bolts and where I could get them?

[PhilGee]

Think they are a 8mm bolt. I've got 2 in my toolbox but have never measured them. Use them for other cars.Normally these drums come off with a tap from the hammer. I've never had any where i've had to use the bolts. Also try using a bit of "freeing off" fluid like wd40 or something. I'm sure you will have had the handbrake released aswell but i've known people try stripping brakes with it on and it only ends up in tears! :D

As sais above, make sure the slave/wheel cylinders arent seized. Seen a few like this with similar fault you are expiriencing.

Let us know how you get on.

[kman1]

Think they are a 8mm bolt. I've got 2 in my toolbox but have never measured them. Use them for other cars.Normally these drums come off with a tap from the hammer. I've never had any where i've had to use the bolts. Also try using a bit of "freeing off" fluid like wd40 or something. I'm sure you will have had the handbrake released aswell but i've known people try stripping brakes with it on and it only ends up in tears! :D

As sais above, make sure the slave/wheel cylinders arent seized. Seen a few like this with similar fault you are expiriencing.

Let us know how you get on.

I've been told that the adjusters on these don't work!!!!..........take the drums off and adjust the rear brakes manually any truth to this? I have noticed that the handbrak is very high.

[PhilGee]

2 types of adjusters on these. One type works, the other doesnt. Without seeing them i cant tell which ones you have. If the adjustment is that far out, it could give you a poor feel to the brakes. The "Naff" adjusters sometimes fall to bits. If they are still intact then adjust them very carefully because they are very brittle and can come apart.

[kman1]

2 types of adjusters on these. One type works, the other doesnt. Without seeing them i cant tell which ones you have. If the adjustment is that far out, it could give you a poor feel to the brakes. The "Naff" adjusters sometimes fall to bits. If they are still intact then adjust them very carefully because they are very brittle and can come apart.

What's the process briefly? I'll try and search to see if their is another thread on this.

[PhilGee]

When you get the drums off locate the adjusters. They sit inbetween the brake shoes above the hub/bearing housing. If you are looking into the passenger side then the adjustment end sits on the left hand brake shoe. Drivers side is the opposite. If you turn the hub to a position where it sits close to the adjuster end, get a flat headed screw driver and push the left hand brake shoe away from the adjuster using the hub as a fixed point to push against. The adjuster wheel should start to turn and click. I do 3 clicks at a time so you dont over adjust it.

Does that make any sense? I'm no good at trying to explain things in detail. I do it day in day out hands on but explaining it over a computer isnt as easy!