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Clutch biting point high and brake pedal feeling soft.


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Hey everyone.  

Firstly, thank you to everyone that warned me about the IS220D and pushed me towards an IS250. Huge improvement and really happy with my new purchase.  

Now the concerning parts,  

Clutch biting point is super high. I'm literally taking my foot off the pedal before the car starts to move. Maybe 1cm at the top. I've done the normal 1st gear - 3rd gear rev test and there's zero slippage with the clutch, i've checked the (brake fluid) reservoir and there's zero black stuff. The fluid is pretty clean almost like it's just been changed (Other fluids seem to be new also. Oil is fresh, coolant is clean etc...) I've checked behind the pedal and see the master cylinder with the pelvis? it looks like it's in the middle of the threads altho is very hard to get it. Should i just bleed the system?  

Front passenger brake seems to clunk if i hold the brake pedal while going over a speed hump. I'm putting this down to the slider pins binding the caliper as the car has been sat for a month+ which a bit of cleaning and grease should sort out.  

Now the brake pedal itself is pretty soft. first half of the pedal seems to do nothing then the last half applies braking force and rapidly becomes stiff close to the floor. Is this a sign that the previous owner has changed the brakes and not bleed the system correctly? Could that also cause air in the clutch system causing the high biting point?  

I've just searched for the last few hours and came back with not much info about DIY repairs. Or even any typical "Repair threads" and many threads get a bunch of random suggestions and no follow up which is not very helpful.  

Anyway could anyone suggest what i should start with and if anyone has any "Repair threads" saved if you could drop me a link that would be super handy. Will be attempting these repairs tomorrow morning.  

Thanks

James.

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Hi James. Re clutch pedal. Being high isn't too bad and is way better than it being on the floor. Plus it makes for quicker gear changes. Re foot brake. Braking is basically in 3 parts. 1st third is partial braking. 2nd third is usually all that's needed to stop. 3rd third is all out lock your wheels up braking.

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37 minutes ago, Mr Vlad said:

Hi James. Re clutch pedal. Being high isn't too bad and is way better than it being on the floor. Plus it makes for quicker gear changes. Re foot brake. Braking is basically in 3 parts. 1st third is partial braking. 2nd third is usually all that's needed to stop. 3rd third is all out lock your wheels up braking.

So having the clutch engage within a 1cm of complete foot removal of the pedal is normal on these? And the only way to adjust that is with that little nut on the "pelvis?" Unsure if that's what it's called.  

The braking is also normal correct?  

If so i guess i've just developed really bad driving habits from a silly little Fiat Punto where it was either no brake or 100% brake lol. Also the clutch pedal normally felt around the midway point of the total pedal travel.  

Like i said the 1st to 3rd clutch test resulted in the revs dropping down and the car picking up speed swiftly so no slip which is a bit of a relief.

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14 minutes ago, ColinBarber said:

You can adjust a little:

I saw that diagram. For me the release point is not like the diagram. It's right at the very top within 1cm of removing my foot from the pedal completely. Other diagrams it would be within the "freeplay" area shown is the best way to describe it.
I'll take a look in the morning. Maybe the freeplay has been removed previously which should lower the biting point a little more. I'm just not used to a clutch being so high so it's a bit worrying thinking "Oh no a clutch is needed" but without any clutch slip it's confusing.

I'll bleed the system first to just to be sure there's no air in the system, then get to adjusting. I'm guessing reassurance is more what i'm looking for.
Also i've just had a look at the Lexus handbook i got and they seem to have a free vehicle healthcheck which might be handy to get booked in for. Maybe they could confirm the clutch pedal maybe.

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You want the biting point to be high up. A worn clutch, air in the system all lead to the biting point getting lower until you don't have enough travel to even disengage the clutch.

However given that it is right at the top then the pedal could be adjusted down and you still have full disengagement.

 

You certainly need a little bit of play at the top, otherwise you risk slipping the clutch.

 

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4 hours ago, MrTrendizzle said:

Now the brake pedal itself is pretty soft. first half of the pedal seems to do nothing then the last half applies braking force and rapidly becomes stiff close to the floor. Is this a sign that the previous owner has changed the brakes and not bleed the system correctly? Could that also cause air in the clutch system causing the high biting point?  

Changing the brake fluid and bleeding the brakes would be the first course of action for a soft brake pedal.

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3 minutes ago, ColinBarber said:

You want the biting point to be high up. A worn clutch, air in the system all lead to the biting point getting lower until you don't have enough travel to even disengage the clutch.

However given that it is right at the top then the pedal could be adjusted down and you still have full disengagement.

 

You certainly need a little bit of play at the top, otherwise you risk slipping the clutch.

 

If that is the case then it sounds like i have a pretty decent clutch and i shouldn't have any worries at all. Just adjust it a little and be happy. Thank you for the diagram and assurance. Hate the panic that sets in after doing a good look around only to start nitpicking little bits thinking it's the end of the world. 🙂

3 minutes ago, Spock66 said:

Changing the brake fluid and bleeding the brakes would be the first course of action for a soft brake pedal.

It might just be the brakes on the IS250. When i turned the engine off and pumped the brakes they became solid and didn't "deflate" at all. But when the engine is running i can pump the brakes make them stiffer and they feel like they're deflating under my foot. Then when it comes to actual braking on the road if i reference MrVlad the 3rd part of the pedal does the stopping wheel lock up braking. While mine dosn't seem to go through the whole 1st and 2nd part of gentle braking unless i have very bad habits and like to brake hard all the time.
I'll still give the brakes and clutch a bleed just to be safe but so far besides these two issues which to be honest is more than likely just me being silly this car is amazing. Heated seats OMG!

Again thank you to everyone that has helped me over my two threads on this forum. I really appreciate it. I'll be back tomorrow with a follow up and results with both bleeding and adjusting with pictures and videos of everything just incase others have the same worries later down the road.

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So today i've been out in the rain, I've loosened the nut which connects to the master cylinder and gave it a few turns clockwise? which has now resulted in a little freeplay before the clutch gets stiff. The biting point is right at the edge of that freeplay tho which from these responses seems normal for this car.  

I did bleed the brakes and there's no air in the system. Unsure how to bleed the clutch. Havn't really looked at that yet. Quick google search results under the car, passenger side of the gearbox should be a nipple sticking out near the slave cylinder? If so should be an easy enough job to get the wife's leg's moving.  

I'll finish this off and see if it makes any difference at all.  

I've got a bunch of pictures that'll post later on as it seems many pictures linked in other threads are now dead or low res Google cached images.

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