Brake Issues - LHD Elan Plus 2 with Weber heads no servo

PostPost by: LaikaTheDog » Mon Mar 08, 2021 9:31 pm

Not seen an elan with dual circuit. But I have seen a similar problem that turned out to be a stuck bias valve . Pedal never went hard even with a thorough bleed with no bubbles.
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PostPost by: The Veg » Wed Mar 10, 2021 1:25 am

Craven wrote:Port nearest the pedal is the primary circuit and is connected to the front brakes.


Assuming of course that it was correctly connected. And if we assume that this is a federal Plus 2, then it would have had a servo when new so if it doesn’t now, then some plumbing has been changed so that the master cylinder now connects directly to the Ts for each end.

I recommend tracing the lines to verify that each circuit is what you think it is.
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PostPost by: nwbaxter66 » Sat Mar 13, 2021 4:15 am

As usual thanks to the great advice received on the forum.
In response to a couple of questions not answered - its a Federal +2 0037N; it did have servos, but removed by PO.

After MityVacing and then traditionally bleeding the system, no real improvement.
Replaced the master cylinder with a TRW version of the same product; bench bled the cylinder, installed, MityVac’d it to get most of the air out, then had the wife push the brake while I operated the bleed end of the process. Result, much improved and satisfactory for track day tomorrow.

Lessons learned -
- don’t buy the cheap master cylinders, or if you do rebuild before installing;
- Mityvac is great for getting the big bubbles out, but even using teflon tape, still doesn’t get the job totally done, but it is quicker

Thanks for the help and advice.

Nick
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PostPost by: Billmack » Sat Mar 13, 2021 5:01 am

Glad to hear you finally got it. Perseverence...
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PostPost by: gherlt » Sat Mar 13, 2021 5:47 am

nwbaxter66 wrote: - Mityvac is great for getting the big bubbles out, but even using teflon tape, still doesn’t get the job totally done, but it is quicker

A German oldtimer Magazine tried bleeding tools and found out that the best tools for one man operation are those tools applying pressure on the reservoir (like Eezibleed), not the vacuum assisted ones (like Mityvac).
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PostPost by: nwbaxter66 » Sat Mar 13, 2021 4:12 pm

In reference to Gheritt’s post.
I have no doubt that the article is accurate, it makes sense and seems logical. However, personally I have never been able to use one of the “pressurize the reservoir” types of bleeders without filling the top of the engine bay with brake fluid.
I think that this one is probably down to personal preference and ones appetite for cleaning up brake fluid (:
Once again, I appreciate the advice.
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PostPost by: gherlt » Sun Mar 14, 2021 5:43 am

I understand that, i used the eezibleed and while the result was fine, I did not like how the refill worked. A too light, unsteady feeling about it. There might be a better, more solid or professional version.
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PostPost by: patrics » Mon Mar 15, 2021 10:00 pm

Hi,
Putting pressurised air over a hygroscopic fluid is a very bad idea. These days a professional pressured system uses an electric pump and in the old days if using compressed air there was a diaphragm between air and fluid.
In production, the vehicles are bled using an evac fill process but that can’t be repeated once the system is wet.
Anyway the Elan system is as basic as it gets, but you need to be aware of one basic thing and that is during the bleed process the fluid takes easiest course and that is in through the hose and out through the bleed screw It does not go around the outer pot pushing the air out.
The easiest way to do this requires the old Girling push back tool – will take a picture and post later. Other stuff: Clear bottle, a tube and willing helper
1. With some fluid in the bottle and tube sitting below the fluid level.
2. Crack the bleed screw a ¼ of a turn and press the pedal down firmly, hold the pedal down fully depressed and lock off the bleed screw. Let the pedal off
3. Repeat until no more bubbles – will only take a few pumps.
4. Remove the brake pad from the out-board side only.
5. Place the Girling pushback tool between piston and disc (Out-board) and pump the brake pedal to push the out-board piston to lightly clamp the tool.
6. Open the bleed screw as before and push the piston back into the housing as swiftly as possible – lock off the bleed screw
7. Repeat 6 until clear – twice should do it as your moving a lot of fluid. This will remove the air in the outer housing and also around the circumference of the piston
8. Refit the out-board pad
9. Remove in-board pad fit the tool
10. Repeat 6
11. Refit pad
12. Carry out a couple of pumps as 2
13. Move on to next caliper

If you look at a schematic of the caliper it will be glaringly obvious why you do this.

If you are racing and change fluid regularly then you always need to do this to replace the fluid in the out-board pot otherwise this fluid is never renewed.

Regards
Steve
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