Braking bad?

[majcd213]

Well I sorted the caliper mounting bolts today. One had sheared but the other was simply missing... leaving a space with the word "Gone" hanging in the air (tribute to the Beano). I got the PNM bolts to refit, but they turned out to be fully threaded which was a disappointment. I also got some titanium motorcycle caliper bolts which do have a short un-threaded shoulder- better than nothing so I refitted the calipers using one original and one new bolt both sides. I took advantage of the strip to change the rear discs too- so I have now renewed or rebuilt everything in the braking system bar the G valve and some of the metal brake pipes.

However this begs the question where the Hell are the bl**** bolts? The car has passed the MOT... twice and I find it hard to believe that it would have done so with one of these bolts obviously absent. Checking the other side showed that these two were both much looser than the 45Nm I had tightened them to. At this point I was reminded of my MGB where caliper bolts are fixed through a long, common tabbed washer strip which is bent tight against the bolt. This presumably implies that there is a tendency for such bolts unscrew themselves with caliper movement (?). I find it hard to believe that this really happens, but unless someone has actually removed them I can't think of another explanation.

So that brings me to what Lotus may have used in this position. Unfortunately these bolts are just not shown in the parts manual- neither as part of the brake calipers nor as a component of the hubs. In my car all four bolts (4 front and 4 rear) were secured though flat and spring washers only- no tabs were present. My question then becomes has anyone got anything different?

I should add that although this has silenced the graunching, eliminated any wobble and given me a nice smooth braking action- its still very inefficient. I know it may improve as the pads bed into their new discs but even so I can still not lock the wheels and pedal travel still seems rather long. I will try adjusting the pedal rods later.
Cheers

Mike

[RED BARON]

Hi. When I took my front calipers off last week they were both only retained by two bolts per side without any washers of any kind, although they weren't at all rusty came off quite easy. I now wonder if they should have any kind off washers like shakeproof or spring type even if the bolts are torqued up to 65lbf.ft.

Ian.

[majcd213]

...or maybe mine shouldn't?

[Hawaiis0]

There is the tendency for some owners to add a little copper slip to the threads as it it usually at hand when doing brakes, to think they will come out easier in 5 years time. Well they do!

[Hawaiis0]

.......

I should add that although this has silenced the graunching, eliminated any wobble and given me a nice smooth braking action- its still very inefficient.....

Mike

Try braking with the left foot only as it usually delivers different pedal pressure. See if that locks the wheels

[majcd213]

There is the tendency for some owners to add a little copper slip to the threads as it it usually at hand when doing brakes, to think they will come out easier in 5 years time. Well they do!

Yep that was me too

[majcd213]

There is the tendency for some owners to add a little copper slip to the threads as it it usually at hand when doing brakes, to think they will come out easier in 5 years time. Well they do!

Yep that was me too!

[Pete Boole]

I use Loctite on these bolts - still disassemble OK.

Pete

[majcd213]

I did adjust the rod which was every bit as pig of a job as I recall... Lotuses not built for 6 footers! Anyway I took up some of the play but as the pedal wasn't bottoming out anyway it didn't really help much. However, I have done 10 miles now on the new discs. I can see a definite improvement. I'm hoping this will improve still further as they bed in. I would like a proper brake test to measure all wheels to make sure it's ok so I may try for that next week.

[majcd213]

Ok Guys... Update. The brakes are definitely improved but still poor and still too long a bpedal travel. I have adjusted the pedal play but I think I must need to adjust the servo to MC rod behind the NC. Everything I've read suggests leaving this alone so I have, but that assumes it was right when I got the car! Nothing else was...
Anyway how physically is it adjusted? It may need to be lengthened so how do I do that? I know the idea is that it just doesn't touch the MC at rest, but is that with the engine running or not... Or doesn't that make a difference?
Cheers
Mike

[majcd213]

SUCCESS!!!

Yep that sorted the problem. I followed the advice given on the site by NickC

"No need to drain fluid just unbolt the master cylinder from the servo and move it away a fraction. Then from inside the car, adopt Lotus position (the servo will be at it's idle position) adjust the clevis on the pedal push-rod until virtually no free movement. Then moving to the outside adjust the servo to master cylinder push-rod so that the master cylinder can be pushed tightly against the servo without the push-rod quite touching the master cylinder. If you have a second person inside the car moving the pedal slightly you can get that rod adjusted to the point where there is just the smallest fraction of free pedal movement before the master cylinder starts to push away from the servo."

I found I needed to unscrew the domed nut by about a half turn. I dont know if this was taking up the 0.3mm extra depth in the landy BMC piston or simply making up for a PO's fiddling but its done the trick. The pedal feels firm much higher now and it brakes like a real car at last! I still havent managed to lock the wheels but it feels much more likely and I'm putting this down to the bedding-in process- I've only done around 30 miles on the new discs and I can see from looking at them that the crosshatching isnt yet evenly rubbed so the pads arent yet lying fully flat- probably should have fitted new ones but there's plenty of pad left on these and time should sort it!

[Pete Boole]

Well done! . Amazing that such a tiny adjustment can make so much difference.

Pete

[bash]

Excellent, perhaps Im not quite as daft as I look eh.

Bash

[CHRISYD]

Excellent, perhaps Im not quite as daft as I look eh.

Bash

celebrate with a pint of mild and some faggots and peas.....i would!!!

[majcd213]

Excellent, perhaps Im not quite as daft as I look eh.

Bash

Wouldnt know-How daft do you look? Thanks for the hint though- I needed a prod to tackle that rod- its easy enough to do, but you have to go against all the Girling warnings and being a law abiding citizen if I'm told not to fiddle with something then I usually don't. However this was very easy to judge when standing outside the car with one foot on the brake and holding the BMC in place with a hand. You can feel when the rod makes contract quite clearly. I'm not sure why fiddling with this adjustment is so discouraged?
Cheers
Mike