HS6 rebuild kit/ needle option

[Forkie]

So - a really awkward Fathers day weekend. After all these discussions, plans etc all is now out of the window. My issue, i now firmly believe, does not lie with the engine - i am back to the brakes. Having took it out yesterday ( Sat) to test the carbs after tweaking , absolutely no difference other than no more popping/ banging through the exhaust - so enriching them slightly has improved that side- even after finding the rear carb needle was seized. Only did sort of circa 4-5 miles , locally. Came back to the garage - could smell 'heat'. Cut to the chase my front wheels were hot - jacked up and the front brakes were 'on' . Plenty more on this topic but for now i will just say ' servo air valve'.....

[Mike Stevens]

I await your next post with bated breath!...

[Forkie]

Wait no more , here it is . Well if there is one example of ' laying a car up does it no good ' - this one is up there
So you may recall ( if the post was read) around a year ago i realised the brakes were not fully releasing. Wont go into that here, no point repeating. So, i was happy in my head that is sorted. But STILL chasing this lack of power. The weekend just gone was the second trip out after full carb rebuilds, the first trip gave a lean condition, so tweaked up the richness. This second trip was to see if any difference. There was, as stated above - the popping had gone, but STILL the power down issue. Back to the nest. It was quite a hot afternoon. Once back, thought it smelt really hot although temperature, as always, reading bang on. I was drawn to feeling the N/S front wheel
Back out with the jack and oh yeah, they are on. Not locked tight but on - effort required to move it - oh my days.Phoned a friend - Google - put in my exact issue, and the type of car - top of the list - servo non return valve - well, not returning....tip - remove vacuum pipe from valve - if the brakes then release, the non return valve is faulty. Removed pipe - no noise incidently - went back to same wheel - now free as a bird.......

[Forkie]

Part 2. So great - another issue , but still progress. I think. Now am i right in saying , for my model - 2500 S - the Servo, Master Cylinder and Non Return Valve are all N.L.A..... PANIC.
Went straight to C.W. site - the only thing he had listed of any of those parts was a ' used' non return valve - brought straight away - along with a load of other stuff, as always i assume as its for sale, it must still be working/ tested.
Back to the car and tests. So the following day ( Sunday) i intended to give the old girl a shower. Start up, into the drive, shower done, back in nest. Couple hours later lets check the N/S front again - tight - again . Released vacuum pipe again - still tight - no difference ????? What is going on here, yesterday it released when pipe removed, today not?
Removed valve from servo - that was a bugger after 50 years - cant blow through either way ( i assume i should be able to blow through FROM the servo side). Refitted. Started her up. Pulled pipe from servo to check suction - immediate idle speed increase and almost took thumb off when placed it on end of pipe - so to me that indicates a good draw from manifold. One other point to make is on starting up i had pumped the pedal beforehand, kept my foot on the brake as i started and the pedal did go down although not drastically. After that lot, rechecked N/S wheel and still not fully released. Shut garage in disgust. Whipped out this eve just so i could give ' current condition ' 2 days later here and it is still not fully released but is slightly better but not the 'free as a bird 'condition i had on the Saturday afternoon.
So, i await the latest bag of parts, hopefully Chris has chucked in a free wig out of sympathy, and any replies to these two posts ' with bated breath....

[johnnydog]

I may have mentioned it previously in a topic somewhere, but I would also be looking at the flexible hose on the affected wheel. With age, the hoses can collapse internally, and when you depress the brake pedal, the normal brake effort required is sufficient to force brake fluid through the brake hose and apply the brakes, but the collapsed hose doesn't allow the fluid to return on releasing the pedal, therefore not releasing the affected brake. This happened on my PI - I was scratching my head as to why the brake was binding after a brake application, and whipping the pads out showed the pistons were retracting when the brake hose was disconnected. Replacement hoses (all round) cured the problem completely.
May or may not be your issue, but worth checking if all else fails.

[Forkie]

Hi John yes you did, but i have the Goodrich braided ones fitted ( new, of course ) and what i should of made clearer was it is both fronts that are snagging - i checked during the weekend it was both - i just keep mentioning the N/S/F only because it is the easiest wheel to get at, for testing purposes, without moving the car about in the garage.

[Forkie]

I think the point i am trying to ask for help on deduction of issue is - i thought my problem of brakes not releasing was sorted a while back. I have now realised that is not the case. Whether they were then, and this is now a ' new' problem i cannot say for sure, but what i can say is they are most deffinately not fully releasing right now, which i suspect may in fact be giving me the feeling of ' lack of engine power' when it maybe more the case of ' engine cannnot go' if that all makes sense. This is where i am at :

After the weekend short run, front wheels were hot ( both wheels). Jacked up BOTH front wheels - both stiff to turn. As in the wheels will move, but only by the amount i physically moved them - in either direction i might add.

Asked Google - top of the list, for a T 2000 with this issue - servo non return valve seized - to test - remove vacuum pipe from said valve - if wheels now free, return valve is faulty. Did this, and wheels now free. At that time car had been out, everything hot.

Next day - removed valve - cannot blow or suck through in either direction - indicator of a stuck or seized valve apparently..... Put everything back together. Started car with foot on brake - pedal went down slightly when engine kicked in. Removed pipe from return valve - idle speed had a rapid increase, thumb almost sucked into vacuum pipe. Put everything back together again. Car not run out other than into drive and back again, so pretty much in a ' cold' state. Engine off . Removed vacuum pipe again from return valve - jacked up wheel - not much difference - still holding - unlike the day before, when all was hot ,then the brakes released.....

So - in short - i have diagnosed - i think - my servo non return valve is faulty as i cannot blow through it either way. I have manifold vaccum drawing from it, as i felt good suction with my thumb/ a fair increase in idle speed when vacuum pipe removed from valve, engine running.

When vacuum pipe from return valve was removed after a run - ( everything hot) the brakes released. When vacuum pipe was removed after just a simple start up and stop (everything cold) - the brakes remained dragging.The engine was off on both occasions of vacuum pipe removal ( appart from testing for actual vacuum). Hope that clarifies my querry - i know the valve is stuck as i cannot blow through it. What is confusing is the difference between the brakes releasing when all is hot, but not when it is cold. Is that an expected scenario.

[Mike Stevens]

As far as I understand, disc brake pads only free off on wheel rotation, so if you moved the car with foot on the brake (it is an auto after all), without any further turning they could feel tight until they release. They 'ought' to be free as a 'bird' when free, as you say.

I think I agree about the non-return valve being faulty when hot (cold?, I've got confused now) so a good used one from Chris should be OK. If the old one was completely blocked, you'd have no 'vacuum' at all and the brakes would need a LOT of pressure - and you'd know about that!

It might be worth removing the wheels and then pads from the calipers to check for free movement there, cleaning out the calipers as you go making sure the anti-squeal shims and hold-in springs look OK.

John's comment about old flexys getting partially blocked is also true, but as you have the problem on both sides, I feel that is less likely especially as you've got braided hoses fitted. Personally, I think they give a much firmer brake pedal than the originals but that might be as I'd compared new braided with old standard ones!

See how it goes with the replaced valve...

[Forkie]

Hi Mike , so the ' hot and cold' aspect of it all was merely wondering if it was normal for - a now known seized return valve - the brakes to 'free up' from the disc after removing the vacuum pipe when everything was hot, but to not do so when it was all cold.
Funny you say about needing a lot of pressure - they do feel very ' wooden' but then i have to remember she has been off road for nigh on a decade and a half, barely a couple of hundred miles since, as all i seem to be doing is chasing problems, but on the other hand all brakes parts are new so not really bedded in, as i cant drive her far !!!! Circles again!!!!! Plus i am used to a 'modern' so i have probably lost the feel really of how they SHOULD feel.
I will, as has been suggested take out the new pads from the new calipers AGAIN to check over but not expecting great piles of grime thats for sure !!! Within the latest CW parcel on it's way i have in fact added another new pad fitting kit as the clips on mine for some odd reason seem to keep moving onto the disc creating a real annoying 'scrape' so new kit will be going on to try and stop that annoyance !!!! Will keep you posted how it goes....

[Forkie]

Had an afternoon free today so thought would get out and do some basic tests.
So - cold car/ engine - been stood for two weeks. Jacked up both fronts - only a very slight rub, on both - maybe very slightly less on O/S. Removed vacuum pipe from servo valve. Jacked up both fronts again - no difference, just the same amount of slight rub.
Next - in to car , pumped brake pedal 2/3 times. ( engine not running)
Jacked both fronts up again - a whole different grab - way tighter,on both fronts - so the front brakes are definately not fully releasing .
Removed vacuum pipe again - not much change, maybe a tad less grab but still tighter hold than before the brake pedal was pumped.
All this was done with no running car as stated, and with everything as it was. Tomorrow will be pads out, check piston movement, fit new retaining kit to pads, and swap servo valve. Just thought i would put this up in case it makes sense to anyone as to where i might be.