Clutch to the floor - 2010 S

[LotusFella]

Hi just went to take the car out for a short spin and the clutch is virtually not there.  I get a very small amount of resistance about 3/4 of the way down but not enough to engage a gear.  how can I check if it's the master cylinder or something else.

Saw the other post like this.  but that just suggest the MC 

thx

[trcm]

Probably the inevitable cooked brake fluid, either way you're going to have to drain and bleed the system, might as well replace the master cylinder whilst you're there.

Check your clutch lines are insulated properly (there was a TSB for that I think) and replace with higher spec fluid, not the Lotus recommended one.

Quote

‘12 MY vehicles from VIN CH_10179 have been fitted with additional protective heat wrapping positioned around the clutch slave cylinder pipe to provide insulation from potential excessive engine bay temperatures. The brake fluid contained within the clutch pipe may exceed its maximum working temperature especially if the vehicle is subjected to either extreme ambient temperatures and/or regular continuous high speed driving.

Vehicles subjected to these conditions have experienced difficultly in engaging or changing gear combined with other symptoms such as very little or no resistance required to depress the clutch pedal or the clutch pedal has failing to return to its original position when released,

Also see Technical Service Bulletin TSB 2011/29 for further details.

Lotus actually don't seem to recommend a particular fluid other than it must be DOT4, and there's mention of getting that from Petronas : 

Quote

• Using only a fresh supply of DOT 4 non-mineral type brake fluid, top up the brake/clutch reservoir as neces- sary - also see service notes section JL.3 for further information.

 

Edited May 12, 2020 by trcm

[LotusFella]

okay thanks worried about possible pressure plate issue.  Any recommendation on high spec fluid?

[trcm]

I think the probable cause of a lot of clutch failures in Evoras is possibly the service garages not completely flushing both clutch and brake lines when they 'replace' the fluid each year.

Hoffmans replaced mine at 10000 miles with 'DLOTAC05385' Brake fluid (whatever that is), my clutch died at 12000, and I dont seem to have a record of what Hexagon used then.

[LotusFella]

yeah fluids looks to be quite dark in colour will try and flush through.

[LotusFella]

can anyone suggest the best way to flush all the fluid please.   Assume I have to do both Brakes and Clutch.

[electro_boy]

Motul RBF660 is recommended a lot for Lotus cars.  Thats what ES motorsports use in my car and is suitable for track use.  Available via Amazon if local shops are closed at the moment.

This is not a definitive list but these are the symptoms I had with my failing master cylinder.

- clutch pedal had no resistance and would fall directly to the floor and not return, required hooking with your foot and bringing back up.

- clutch pedal would also pump up, eg soft at first then stiffen up, like when you have air bubble in the break pipe that works its way out to reservoir.

- brake in the reservoir was a little brown and cloudy.

- there was no noises coming from the engine bay, eg pressure plate making any grinding noises etc.  There was no knottiness felt in the clutch pedal as if something mechanical in the system was broken or damaged.  Just a smooth pedal with no resistance, until the pedal pumped up and then normal operation would resume for a bit till it went soft again.

The master cylinder is in the front clam and I don't think there is a way to access it without taking the clam off.  Maybe if you have a endoscope thingy you might be able to stick through some hole and locate the master cylinder to see if its leaking etc? 

To flush fluid without a bleeder tool.  You can open the bleed nipple on one calliper and pump the break pedal while adding new fluid to the reservoir making sure it does not go dry. Keep pumping till fresh oil comes out the bleed nipple with no bubbles.  repeat for all four corners.  Similar process for the clutch but you need to open the bleed nipple on the clutch slave cylinder which is in the engine bay above the gear box.  There is a post on the lotus talk about bleeding the clutch.  I think you may have to remove the airbox system to get a decent view of it. 

[Bibs]

1 hour ago, electro_boy said:

repeat for all four corners

Go from the brake furthest away and work your way to the one closest too. 

[Painterdave]

Be careful not to get the brake fluid on your paint as it's corrosive

[electro_boy]

The local garage used about 1.5 litres to do a full flush of the brakes and clutch system.

[LotusFella]

okay thanks guys.  I have an air line bleeder connected to the slave cylinder bleed nipple.  silly question but do I need to pump the clutch pedal to bleed?  As I'm getting loads of air coming out, a little fluid but the reservoir levels is not dropping.  Master cylinder just sucking in air from around seal i guess.😪😪😢

 

Anyone know what master cylinder it is or do I just get one from deroure.com?

 

Thanks for all the info.  Not sure if this is connected to the stutter but I don't think so. 

[trcm]

I hope they have one in stock, I waited three months 😪

[LotusFella]

3 minutes ago, trcm said:

I hope they have one in stock, I waited three months 😪

Bloody hell hope so!  

[trcm]

There’s always the option of the Willwood master cylinder if you can’t get the plastic Lotus one. 

[2011 Chrome Orange]

LotusFella, no need to pump the clutch. Just make sure you have a good connection with the bleed hose on the slave bleed nipple and do not open the bleed nipple more than you have to or you can pull air from the nipple threads while vacuum bleeding.

Other option if you aren't successful... pressure bleed from the master so that there is no air introduced at the bleed nipple. Several guys over here have performed a good bleed and got the pedal back. Lotus recommends every two years, if I remember right. But, I bleed every year with Castrol SRF React Racing fluid. Its pricey but I have never had an issue. Also, while you are there, check for the heat wrap on the slave line as mentioned above. If you don't have it......it's pretty much a must have to prevent further issues.

Also, I'm not sure about your right hand cars, but on our left hand cars, master cylinder replacement has been done through the left wheel well. I haven't done it myself, but it has been done. Although, my guess is it would be much easier with the clam off if you haven't done one before (if I ever have to replace mine, I'll be doing clam off).

 

[LotusFella]

cheers.

[Scotsdave]

I had this issue back in January. Its not possible to change the master cylinder on RHD cars with the clam on. 

You have to remove the clam and you need two people to remove the master cylinder as its held in with nuts and bolts that aren't captive.

We did it with an easibleed on the master cylinder pushing the fluid out the slave cylinder. It took my dealer a couple of days to get a master cylinder they told me Lotus had plenty in stock at the warehouse.

If your doing it I would also recommend replacing your mud flap brackets if you haven't already as they will probably be dust and flapping in the wind (They are made by a user on the forum but now sold on Ebay by a third party) . Also check out the condition of your A/C condenser as it makes sense to swap that at the same time as having the clam off.

Davie

[LotusFella]

Thx.  Yes mud flaps bracket done.  Only just finished re lacquering the headlights last week 🙄 at least i know how that comes apart?  is it obvious where the clam bolts are? 

[LotusFella]

Anything else I should be checking replacing if taking of front clam?  I will check/clean rad

[Scotsdave]

Just the AC condenser there not alot under there.

The bolts are where you would expect nothing is really hidden. 

Splash guards out, Headlights out, front badge off. You'll find three bolts here.

Each side of the bumper has three screws where it meets the clam behind the headlights.

Open the front hatch and undo the bolts there holding the clam and washer bottle filler. Undo the 2 bolts that go through the hatch latch and release the cable. Leave the hatch on the clam no need to remove it.

Then you have bolts behind the A panels you have a couple of options here. Remember to unplug the side repeaters.

It should lift off now. It will take a couple of hours to remove and about a day to refit. Lining up the headlights is a horrible job.

Once the clam is off you then need to remove the cowling on top of the radiator. Be prepared to swear at this point as all the fasteners are stuck or rotten.

You can leave the bumper on and bolted to the undertray.

The perfect lockdown job.

Hope that helps

Davie

[LotusFella]

Thanks Davie. Condenser is the radiator part right? Receiver dryer also? Don’t want to change unnecessarily. The car is 10 years old this year, but the ac is still nice and cold. Can I tell visually if they need replacing? 

[electro_boy]

Normally they fail due to stones or debris hitting them. So just give it a visual inspection check dents and damage. 

[Scotsdave]

If the AC is still cold your probably ok. Yes the condenser is the radiator.

Mine was rotten and bent like a banana.

Edited May 15, 2020 by Scotsdave

[LotusFella]

Any pearls of wisdom that can help me get these bolts out with breaking the clam mounts!  It already looks cracked on nearside😤😤😭😭

[LotusFella]

What fucking knob at Lotus designed the mild steel nut moulded into the clam with a mild steel bolt!  Fucking madness🤬🤬🤬🤬🤬🤬🤬🤬🤬🤬🤬🤬🤬🤬🤬🤬🤬🤬🤬🤬🤬🤬🤬🤬🤬🤬🤬 

Both sides rusted solid!