NH TM125 brakes

[dave7840]

Having problems with the brakes on our tm, it started last year, the right peddle would creep down if you put pressure on it, I bled them and no difference. So I change the right master cylinder and change the discs and seals because it was due a service and they had never been done (9500h and they looked the same as the new ones), which cured it. Now about a month ago I noticed the right hand peddle was creeping again, so change the master cylinder again. Problem solved for two weeks, it is now creeping again. I have swapped the pipes left to right behind the right steps and the problem stays on the right peddle, so that should mean that the problem is still that master cylinder, right?

 

[Mur Huwcun]

IS your fluid (LHM) going down at all. IIRC trailer brake valve is on R/H side and can leak internally. You have bleed the TBV seperately ir on yours is it an extension from the trumpet housing?

 

[dave7840]

fluid isn't going down. The tbv is bled. I've read they can leak. I've swapped the pipes in the middle,which is before the tbv and trumpets and the problem stays on that right peddle. It would move the problem to the left peddle if it was behind where I've swapped it. Would it not?

 

[Mur Huwcun]

I would think so yes. One thing to check but if it bleeds up ok it shouldn't be a problem but is there a restricion between reservoir and cylinder?

 

[dave7840]

i changed the hoses and clips from the reservoir to the master cylinder the first time i changed the master cylinder. The company I got the master cylinder off were funny about replacing it last time i dont know that they are going to do it again, but its the only thing I can think it can be. I did get a blanker to fit the hose from the MC, but even though its the right size and thread, it won't go on

 

[diesel druggie]

What about front axle braking. Had one here leaking years back. Blank it off before it enters the axle and see what happens.

 

[agrimax]

If I'm not mistaken,the mc would be the only place the fluid could get past the piston seal but still stay in the system hence the fluid not going down.Anywhere else leaking by would surely let the fluid into the oil or out externally and would need topping up frequently. A weak flexi hose anywhere in the system would also give the symptoms but the problem wouldn't have went away after the two mc changes. Have these replacement mcs definately had green seals in them to suit lhm fluid?