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Anon
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TL rear brake imbalance - any clues?

Hi all
We are having a problem with a poor brake on the rear n/s of a UK 1990 AWD TL 8-14 (looks to be pretty much the standard TL/TK setup).

The rear wheels have both had new liners, new cylinders, a new spring chamber, master cylinder overhauled and the o/s is fine. However the n/s simply will not come up with anything like the expected efficiency so we are failing the VOSA test on brake imbalance (it has enough efficiency to pass by itself but is too weak compared the o/s wheel).

It is failing on both parking and service brakes with this imbalance.

The TL is currently being looked at by a load of fitters, some of whom have been in the business 30 years plus, and we are all bamboozled.

If anybody has any ideas at all then can you shout out? (we have ruled out lack of bedding in, contaminated liners/drum and so on but given that the weakness is on both service & parking brakes we're thinking it must be something common to both systems but just what?)

Thanks

Graeme


p.s. here's the actual work done - the original problem was with the O/S

1) Fails VOSA on an O/S brake weak due to contaminated linings
2) Pull hub - cylinder seals leaking
3) New O/S cylinder, new linings both sides
4) N/S is now weak
5) Replace spring chamber, overhaul master cylinder
6) N/S still weak
7) Pull hub again, new N/S cylinder, all other parts rechecked.
8) N/S still weak
Tue 27 Mar 2012 @ 12:50 Edit this messageQuote this messagePMQuote this message
Anon
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If the rear cylinders are the type with a pull rod through them (E series air over hydraulic) then check the balance (relay) lever for seizure on its shaft.

Need to disconnect link rods to try moving lever by hand to be sure; don't rely on seeing lever moving when brakes applied.

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Tue 27 Mar 2012 @ 13:04 Edit this messageQuote this messagePMQuote this message
Anon
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Hi Phil

Yes - it has the sort of pull rod brakes you describe that link cylinder to a crank mounted above the diff.

I'll give this a shot - thanks for the swift reply

Graeme
Tue 27 Mar 2012 @ 13:41 Edit this messageQuote this messagePMQuote this message
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