Need help figuring out a BRAKE warning light cause

[h00kem]

When I purchased my 86 Turbo Esprit HCi the BRAKE warning light on the dash was constantly on. I have been trying to figure out why. I assume it is warning me that the brake fluid is low. I made sure that the fluid reservoir is full of brake fluid. Next I tested the cap on top of the reservoir with the two connected wires to make sure the low fluid switch was working...it is. Just for good measure I replaced the cap to be sure the switch was ok. The BRAKE warning light is still on. Tonight while looking around for other possible problems I noted what I show it the two pictures attached. In the first picture there is some sort of off-white plastic device that connects the bottom of the servo-brake booster. I noticed that the device has a nipple for a hose connection but there is no hose connected to to it (see arrow). Anyone know what the off-white plastic device is? Should the open nipple be connected to something? My next questions are about the second picture ...coming off the servo-brake booster is a black hose, I assume a vacuum hose, with an in-line tee connector. The smaller hose coming off the tee is capped and nothing is connected to it. It is possible that the nipple without anything connected to it and hose coming off the tee without anything connected to is might be related? My final question...any ideas on what I might check that would cause the BRAKE warning light to remain on? The brakes on the car seem to work just fine. HELP!

[lotus4s]

I'm not familiar with the braking system on your car but in looking at the parts manual I believe that the plastic piece in your first pic is a "low vacuum switch" and it appears to be hooked to the "T" in your second pic.

Edited February 16, 2010 by lotus4s

[andydclements]

Spot on by Jim.

It's the switch that will be your first warning when the vacuum pump stops (belt slipping or whatever) so you really should connect it up.

[h00kem]

Thanks guys. So I assume that you are suggesting that the two items (the nipple on the off-white piece in the first pic) hooked to the second connection that is now capped in the second pic. Correct?

[andydclements]

Yes.

I am concerned that there may be a fault (air leak) on that switch that caused the previous owner to disconnect it and plug up the hose, else I cannot think why that would have been done.

If it is the case, replace the switch, or else you'll not know if the vacuum system starts to leak, or brake fluid is low, or even if the handbrake is left on, none of which are good.

[h00kem]

Thanks. I agree, it needs to be corrected. I too cannot imagine why the prior owner appears to have disconnected...perhaps it is because a replacement switch is $155 from Lotus! Oh well, $155 will seem really cheap when the brakes fail and I am headed into the beyond. Thanks again for the help guys. I really appreciate it!

[lotus4s]

Kevin,

Where did you get that price, it sounds awfully expensive? Did you try Jeff and Jay at JAE?

[h00kem]

Kevin,

Where did you get that price, it sounds awfully expensive? Did you try Jeff and Jay at JAE?

Yes, Jeff at JAE said that the part is no longer manufactured so they would have to go direct to Lotus and their old stock.

[Mesprit87]

Hi,

You didn't specify if it was the handbrake light or the brake fail warning light... I know the hand brake light is intermittent on mine, just could be the same on yours.

If it is the brake fail light you can try the following:

Before buying a switch, just disconnect the connector and see if your light turns off.

On the wiring manual, it show open for the light to stay off.

By the way, I checked my car and confirm the hose has to be connected.

Good luck

[h00kem]

Thanks very much for the suggestions. It is the brake fail light...not the handbrake light. I'll connect these up and see if it fixes the problem. If not, I'll disconnect the connector and see what happens.

[h00kem]

Finally found some time to get back to the car. Connected the two plugged off line to the nipple on the piece that sits at the bottom of he brake boost... and now no brake warning light! I have no idea why the prior owner disconnected but the simple fix corrected the problem. Anyway, thanks for the help guys.