Servo push rod adjustment

[ethel]

Ok, on to the next stage and more questions.
With the brake MC and servo apart I checked the length of the push rod and the depth of the hole/socket in the master cylinder, both relative to the cylinder mounting face and found there was about 3.5mm gap or free play between them. From what I can find on the net the gap should be about 0.015inches, so I need to lengthen the rod. It looks like the hex on the adjustable end and its locknut are 7mma/f, I would have thought 1/4" or 3/8" would be more likely, but they are too small and too large respectively, also my 5/16" box spanner is too big. Of course, 7mm is the only size spanner I don't have and it needs two of them! I did try with an adjustable but if I put any more load on it the hex will round off, so I'd rather use a proper sized spanner.
Can someone confirm the 7mm size, what servo rod freeplay should be and that the length can vary by upto at least 3mm - the master cylinder has definitely been replaced in the past without this adjustment being made.
Thanks, John.

[Phil S]

mole grips and an adjustable should do the job, yes the adjuster bolt should be long enough to take up that much

[richardthestag]

refit the servo to the car and attach it to the brake pedal, then get a helpful assistant to push down the brake pedal and hold it there.

the pushrod and all the adjusters are now hanging out the front face of the unit and simple spanner job

[ethel]

I used a strap around the servo and brake pedal clevis to make the rod poke out so I could reach it, though I'm still worried that an adjustable or mole grips are just going to bugger it up.
John.

[ethel]

I think I might have got it, can you tell me if this is right.....
From its appearance I assumed that there was threaded cap on a rod with a locknut to keep the cap in place and that the rod was part of the unthreaded rod that continues into the servo diaphragm. However I've just unscrewed the threaded rod from the inner rod and it looks like the threaded rod is all one piece with the nose. What I thought was a locknut is where, for some reason that I can't see, there are two hexagons machined next to each other - no wonder I couldn't undo the 'locknut'.
So I've just got to screw the threaded rod back in to the correct depth and hope it stays at that position - maybe some thread lock would be a good idea.
John.

[Phil S]

all the ones I have seen have a lock nut, if you can't find a nut the correct thread I would suggest you use thread lock

[ethel]

If I'm right with my assumption in post 5, then originally the rod was screwed in to the servo so far that there wasn't room for a locknut....maybe that accounts for why it needed so much adjustment.

[richardthestag]

Spare stag servo that I have is the same as your John, i.e. two hex faces as part of one single machining.

+1000 to thread lock

[Alacrity]

This interesting as I fitted a new brake master cyl to mine as part of a total brake overhaul after it had stood for 33 years & it always had long pedal, with free play at the top of the pedal, clearly this needs setting up but I hadn't found any info on how to do it. The car is a bare shell sans paint currently & the servo is on my list of things to overhaul before refitting, so this is good info. Many thanks.

[jbuckl]

Pushrod must not be too far forwards so as to cut off the recuperation ports.

[MandM]

Where is the stated servo push rod to master cyclinder gap cant seem to find it in the ROM, 0.2mm on the net for other cars but what about the stag ?

[sujitroy]

I'm on my phone but Terry Hunt sent me a doc on that. Lockheed hydraulic equipment on the Triumph stag. send me an email. I'll send it. Triumphstag@gmail.com. I'm at work and at work and soc forum is blocked

[jbuckl]

Minimise the gap.

ensure there is a gap.

Do not compromise Fluid recuperation….by over extending.

get suitable tools…..or leave well alone.

[MandM]

I'm on my phone but Terry Hunt sent me a doc on that. Lockheed hydraulic equipment on the Triumph stag. send me an email. I'll send it. Triumphstag@gmail.com. I'm at work and at work and soc forum is blocked

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