The cheapest way to upgrade the brakes.

[david924s]

Have a look here for the modification Jamie N did using Honda Civic typeR rear calipers which should be readily available in the US, he has done this a few times now I believe and I bought his SE with this conversion on and can attest to the quality of the handbrake and stopping power. viewtopic.php?f=41&t=26878&p=351412&hilit=brake+upgrade#p343409

[peter canepa]

My mechanic is suggesting something I have never seen posted about the brakes. He claims there is not enough boost. The vacuum volume in the booster is not enough. When you first step on the brakes, they feel great but as you continue, there is less and less power. He set up a test, a scuba tank and a hose to give the booster more volume. He claims it improved and we are now adding a permanent small tank mounted under the hood.
Anyone ever tried this? Stay tuned I pick up the car tomorrow.
Peter

[378S2]

My mechanic is suggesting something I have never seen posted about the brakes. He claims there is not enough boost. The vacuum volume in the booster is not enough. When you first step on the brakes, they feel great but as you continue, there is less and less power. He set up a test, a scuba tank and a hose to give the booster more volume. He claims it improved and we are now adding a permanent small tank mounted under the hood.
Anyone ever tried this? Stay tuned I pick up the car tomorrow.
Peter

How did it work out? This would be a very easy modification.

[peter canepa]

Sorry not to finish this thread. The results are fantastic! Just to review, after a test drive the mechanic, seemed to believe that there was not enough vacuum pressure. He noticed when you hit the peddle it would start firm and as you brake it would get softer. He added a beer can size reservoir to the system, thus increasing the tank. He tucked above the wheel well, drivers side, behind the plastics fender guard, ran a hose up to the brake pump added a T. Its really amazing and its super simple.

[robertverhey]

Sorry not to finish this thread. The results are fantastic! Just to review, after a test drive the mechanic, seemed to believe that there was not enough vacuum pressure. He noticed when you hit the peddle it would start firm and as you brake it would get softer. He added a beer can size reservoir to the system, thus increasing the tank. He tucked above the wheel well, drivers side, behind the plastics fender guard, ran a hose up to the brake pump added a T. Its really amazing and its super simple.

This is of great interest to me because I am poised and ready to fit my smaller diameter M/C, a job which promises to be a real pain, The M/C mounting bolts are very hard to access, as previously documented, and bleeding all the air out can be tricky, it seems.further, some concerns have been raised regarding loss of braking should one circuit fail.

A supplementary vacuum reservoir is a much less invasive option. However all the ones sold on eBay are 2 litre ones unlikely to fit behind the wheel arch liner. Do you know where your mechanic sourced the smaller coke can sized one? Do you have any pics?

[peter canepa]

Robert,
My mechanic and I talked about master cylinders and bigger brake servo. From the posts on this site, the Mstr Cyl does not solve anything. The Servo probably would, but that is a big project. We decided to start with the vacuum tank. He fabricated it. We didn't get any pics. Believe me I told him this would be of value. Let me this week, jack the car, remove the front wheel, take the fender liner out and get some photos.
Peter

[peter canepa]

Robert, It ain't pretty, but in his defense, this was a test of the concept. Its 2000 lb car, it shouldn't need a much to stop it. The 2nd photo shows the hose from the reservoir connected to a T

[lotusflasherman]

My mechanic is suggesting something I have never seen posted about the brakes. He claims there is not enough boost. The vacuum volume in the booster is not enough. When you first step on the brakes, they feel great but as you continue, there is less and less power. He set up a test, a scuba tank and a hose to give the booster more volume. He claims it improved and we are now adding a permanent small tank mounted under the hood.
Anyone ever tried this? Stay tuned I pick up the car tomorrow.
Peter

Ridiculous ! Suggest you check the servo non-return valve and servo diaphragm and find a new mechanic. Nobody else has done it because nobody else needs it. When braking the throttle is closed, the brakes are slowing the car and the engine - which produces maximum vacuum in the plenum chamber which in turn opens the servo non-return valve and continues to feed 'vacuum' to the servo ... an extra tank is superfluous!

This may be useful .. brake-servo-fault-finding-guide/

[robertverhey]

My mechanic is suggesting something I have never seen posted about the brakes. He claims there is not enough boost. The vacuum volume in the booster is not enough. When you first step on the brakes, they feel great but as you continue, there is less and less power. He set up a test, a scuba tank and a hose to give the booster more volume. He claims it improved and we are now adding a permanent small tank mounted under the hood.
Anyone ever tried this? Stay tuned I pick up the car tomorrow.
Peter

Ridiculous ! Suggest you check the servo non-return valve and servo diaphragm and find a new mechanic. Nobody else has done it because nobody else needs it. When braking the throttle is closed, the brakes are slowing the car and the engine - which produces maximum vacuum in the plenum chamber which in turn opens the servo non-return valve and continues to feed 'vacuum' to the servo ... an extra tank is superfluous!

This may be useful .. brake-servo-fault-finding-guide/

Also interesting. If I understand the rationale behind the supplementary vacuum tank, however, it’s to remedy situations where several repeated jabs at the brakes are needed….I’ve noticed our family’s audis and vws run out of “puff” quite readily while manoeuvring down my steep drive. Might do some experimenting next time I have the elan out.

Anyway these are the tanks sold on eBay, quite a few sellers, so I’m thinking insufficient vacuum capacity might be common in some other cars as well?

https://www.ebay.com.au/itm/174922950956

[donsladek]

Or maybe one of these if you've got that lumpy idle:
Electric Vacuum Pump

[19peace84]

Hi sorry to jump on this old thread, I've just got a m100 and the brakes are awful, is there anywhere with these master cylinders in stock?

Cheers

[Jamie N]

I have front and rear modern upgrades, 2 full sets available, less than half the price of any other upgrades with just as good performance, especially in terms of the handbrake.
Sure there will be a few owners here that can testify. No modifications just bolt them on.

[Fredjohn]

Hi sorry to jump on this old thread, I've just got a m100 and the brakes are awful, is there anywhere with these master cylinders in stock?

Cheers

Master cylinders are available from the usual classic Lotus dealers. Eg SWLC, SJ Sports Cars and Classic Team Lotus.
It's a pig of a job to change. Before doing so it may be better and easier to refurbish each corner, viz pads sliders and possibly discs. Then bleed profusely!
Or take up Jamie N's offer of updated (upgraded) kit.
Also helps to add your location to narrow down suppliers and possible hands on help.

[19peace84]

I have front and rear modern upgrades, 2 full sets available, less than half the price of any other upgrades with just as good performance, especially in terms of the handbrake.
Sure there will be a few owners here that can testify. No modifications just bolt them on.

What's the price pal?