33 replies to this topic

[baldric]

images of master cylinder   P1020047.jpg   124.86K   16 downloads  P1020048.jpg   147.8K   11 downloads  P1020049.jpg   156.64K   9 downloads

 

images of master cylinder  cleaned up cylinder pushrod  new clevis pin fitted oversized  9mm  clevis pin 9mm holes reamed to 9mm 

 

cluster box  in the vice   cylinder push rod fully retracted  all set up as it would be in the vehicle

 

cylinder pushrod on full stroke which meets up tight with rubber boot ferrel  that is the limit of its travel without pedal stop

[baldric]

the images will enlarge   ,,, not very  computer  literate  this end

master cylinder  set up    washers represent bulkhead thickness this way I can check whats going on ,,, with the clevis pin in position & right at the pedal  tip  I get  1/16" inch free play and that is allowing  the clevis pin to be one thow undersize of the pedal reamed hole  ,,,which is not bad  , could be better , this goes to show that a fraction of an inch   compound  itself  over the length  of the pedal  assembly , call it free movement,

 

pedal movement in the old  pedal box cluster   was  close to 5/16"   this was before any movement in the master cylinder  no stop fitted

 

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 P1020050.jpg   171.68K   15 downloads

[baldric]

ok lets look at this little lot

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•  P1020051.jpg   116.18K   11 downloads

[baldric]

I was too quick with the key with that image
the thru  bolt ,,, the spacer that is spot welded to the side of the cluster box ,,, see how it has worn oval which means disaster ,,,
 
the thru bolt  look at the thread , its threaded all the way to the hilt of the bolt  the thread should end 5mm away from the hilt of the bolt    ( why do you say  )  it acted like a cutter on the spacer  when the brake pedal  was seized on the thru bolt ,,, now go to the other end of the bolt next to the hex head  (might haft to enlarge image )   look how the  ware is  , a defiant  grove all the way around ,,, why ,,,  the thru bolt was waring on the thin side of the pedal cluster box side
 
clevis pins   no  1&2  new pins  they are turned from  silver steel   ,,, and if you are in the states ,,,  commonly known  as drill rod
no 3  original   clevis pin   badly worn   ( enlarge the image to see )    pin  no 4   that  is  a standard  size  clevis  pin
 
slave cylinder push rods ,,,the first one is turned out of a grade 8 bolt ready to be shortened    right no 2  mongrel  this is what I found lurking in the slave cylinder  ( if I could find the bloke who done this ide kick his arse blue) also see how the clevis pin eye has worn oval  ,,, n3&4 original  pins  ( not cleaned )  fit for the scrapbox    simple reason  look at the eyes   worn oval   ,,,  and have no further use
 
clevis pins   mod   the new pins will have a hole drilled down the shouldered end  so a wire can be pushed in  and bent at right angle  this will make the sodin things easier to fit   the clevis pin eye  will be fitted with a R clip   the brake side will be fitted with a split pin  R clips are not to be trusted on a brake clevis pin  bit dangerous   could land up a bit mangled in the middle of the road  waiting  for the meat wagon , if the R clip was to fall out  ,,, if it comes to that  fit split pins to both brake and clutch  clevis pins
baldric

Edited by baldric, 23 October 2013 - 10:55 AM.

[baldric]

these two bulk-head fixing brackets had to be straightened out , they wer like a couple of gull wings
 P1020053.jpg   131.6K   4 downloads
I decided to have a go at the brake master cylinder removed the fluid cup , be very carefull of the two bolts holding the resavor if buying new ones size 1/4" inch unc ,,they are not whitworth different thread angle although they look like whitworth

 P1020063.jpg   176.84K   1 downloads    this is what happens when moisture mixes with brake fluid

this was a nasty surprise that has to be sorted I am surprised that the fluid never leaked from that joint so into the mill it went for surfacing fluid cup cleaned out with detergent and a tooth brush
 P1020066.jpg   129.97K   4 downloads

Attached Files

•  P1020054.jpg   327.97K   3 downloads

Edited by baldric, 23 October 2013 - 12:16 PM.

[baldric]

 P1020062.jpg   45.37K   4 downloads

whilst I was at it , I checked the slack in the pedal clevis using a brand new clevis pin standard size

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take a look at the bottom of the pedal and note the measurement to the next image

 P1020062.jpg   45.37K   4 downloads

that is not good so out it comes for a new oversized pin 9mm piston pushrod fork reamed removed pedal for reaming ,,, the full stroke of the master cylinder 1" 1/4"

 P1020061.jpg   137.62K   4 downloads
3/8" inch play that is a lot

I am not suggesting every ones pedal cluster is like this one ,,, lets face it you have a 50 year old mini the pedal box cluster is not going to be in grate shape people spend umpteen pounds on there shells and gadgets ,,, just spare a thought to the pedal cluster it could mean disaster for your nice shiney new vehicle its is as important as your brakes

Edited by baldric, 23 October 2013 - 11:01 AM.

[baldric]

brake master cylinder in order to assemble cylinder with newely milled face this cylinder uses 1/4" UNC bolts like some other bolts on this vehicle the fine thread ones UNF one thing to look out for is the thin brass coloured shim this is a non return valve ,or reed valve as I know them it goes on the end of the piston ,,, in the end of the piston there 3 small holes drilled for fluid to pass through in pedal down mode the force of fluid being pushed to the brakes forces the neoprene piston seal against the top of the piston shim closing the ports off ,,, when the piston is in reverse mode pressure is released from the piston and fluid is drawn through the three holes ,,, to replenish fluid that leaked away ,,,in other-words this valve keeps the lines charged with fluid and keeps the pedal set ,,, don't bend that shim nor loose it or forget to put it back in the piston

 P1020068.jpg   124.91K   7 downloads

the reed valve is the 3 item up from the circlip ,,,about circlips its advisible to fit new ones they do get a bit tired and loose there tension ,,, there also a reed valve in the master slave cylinder don't damage it ,,, the brake pedal after reaming and fitting new clevis pin is down to 1/16" free play at the tip too small to show on camera that's a big improvement over 3/8" inch

Edited by baldric, 21 October 2013 - 03:53 PM.

[baldric]

lets look at this bit , first impression single manifold gasket ( it aint ) it goes under one of the master cylinders --- brake or clutch
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there is a good reason for this the two master cylinders do not have the same stroke the clutch cylinder has a shorter stroke ( for some unknown reason , but not on all vehicles) this shim serves a very important job

don't take any notice of the large washers they represent the thickness of the cross beam and the cylinder tray ,,, that's where the washer/shim fits its important! how many of you complained about one pedal being higher than the other
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this shim is for that reason only and no other has nothing to do with the hydraulics of the clutch master cylinder (zilch) ,,, pedals not level
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this is what it does


the brake pedal plate has a bit of twist ,,, but you can see what it definitely does its there only to level the pedals ( not like some other silly explanations I have red ,,,only the other day some one was asking how to level his pedals , and this is the only way levelling can be done ,,, what happens you lift the clutch master cylinder physically then the toe of the clutch foot pedal drops , mind you one has to have good clevis pins and the piston push rod fork needs to be in good shape fitting new clevis pins without addressing the fork ware and pedal clevis pin hole in the pedal ( is no good) a proper job has to be done of the whole system to get things back to as and when the vehicle was new

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Edited by baldric, 22 October 2013 - 01:04 PM.

[Ethel]

The dual circuit brake pedal is deliberately cranked further away from the floor so you don't run out of pedal travel if a circuit fails. If you want level pedals it'd be better to raise the clutch pedal. The Metro clutch Master is a smaller bore, so you might manage to incorporate that and get a lighter clutch into the bargain.

[baldric]

clutch slave cylinder , hel its a non standard part that not a problem to me it gets used as long as it works that's all you have to worry about
 P1020076.jpg   112.33K   3 downloads
please don't take any notice of the measurments the correct measurement of the stroke of the slave 1" 3/8" these are ball park figures ,,, that is piston fully down to the piston fully released against the circlip there is no blanking of the fluid holes either in the outlet or bleed nipple that also goes for the master cylinders the master has a stroke of 1" 1/4" stroke and I would expect that at the slave cylinder , but but, in the real world that not always the case , like air in the system and slight compression of fluid and other things like the slight expansion of the flexible hose , bulkhead to engine

now the next picture is the sort of thing you haft to expect of a 50 year old vehicle
 P1020078.jpg   184.7K   7 downloads

this is the side of the pedal cluster box the image is taken through the lightening hole on the left hand side look at the small drilling where the pedal cluster bolt fits through see how much it has worn I had to take the spacer off the other side which had been spot welded on and a new spacer fitted and spotted ,,,, I honestly don't think it is worth buying a second hand pedal box all the joints and welds need to be inspected as well as clevis pins and master cylinder push rod fork ends personally I am getting out of it very cheaply around about $17 bucks as apposed to a couple of hundred may be quid

[baldric]

ethel

I know the metro cylinder  granted  a lighter pedal  with a small bore   I have a sneaky suspicion one would haft to change the slave as well or is the bore the same as the mini  ,,, what I am thinking  metro cylinder is moving a small volume of fluid into a larger slave cylinder  would this not end up getting less stroke in the mini slave cylinder  ,,, I don't know  haven't worked it out yet  so its open to conjecture

 

pedal box gets painted to morrow  greas nipple fitted to the pedal cluster bolt  then its fingers crossed that the silly thing works 

 

that was the main problem  the pedals hitting the deck ,,, and the thicker the sound proofing  bigger the problem  a  lot has to do with that cross beam ,  if it gets rust cut out of it  , its important that it goes back in exactly the same position or a whisker higher  to lift the pedals a little more off the floor  the full pedal stroke from the pedal toe to full down stroke  is  6" 1/4"  inches  and that's with a master cylinder  piston stroke  1" 1/4" that's on my cluster   easiest method to check  push clutch pedal down   and just check with the flat of your hand  behind the heel of the pedal arm if that works and aint too tight  you have no future problems if the heel touches the floor   ,  its  oh  bugger

baldric

Edited by baldric, 22 October 2013 - 02:17 PM.

[baldric]

the master cylinders  I will rabit on about that,  no matter how much stroke you have  , bottom to top, the piston  will never fowl the resivoir inlet port  either in the brake or clutch master cylinder  in the clutch cylinder  the piston is wasted  this enables the piston to draw liquid from the resivoir   into the wasted section of the metal piston from there  when the piston is in the down stroke,  the fluid gets drawn into the head of the pistons black neoprene  black seal,,, direct     below that neoprene  seal there is a small shim  that sits on the actual metal piston ,,, the metal piston has three holes drilled in the top to transfer  fluid on the pedal down stroke,  and the force of fluid on top of the neoprene piston cup  transfers pressure to that shim and closes the three holes off   , basically it is a reed valve ,,, when the foot is taken off the pedal  , you have a reverse action  ,  the fluid moves up the three holes opens the reed valve and passes up past the neoprene piston  replenishing what fluid is lost  a simple and effective  system providing you don't nacker that small shim reed valve ,,, why do they use a shim reed   , simply  the piston cup is neoprene  and for the amount of times that piston works  the drillings in the top of the metal piston would be chewing its way through the neoprene piston and after awhile you would get leak back into the resivor  very hard to detect   ,,,  one way    ,   foot hard on the pedal  watch the clutch arm to see if there is any return movement  of the clutch arm  coming  to rest   if you have no other fluid leaks in the system no air in system  ,  a pound to a pinch of dirt  that's the problem   ,,,   rust craters or plane rust around the ends of the clutch piston  called corrosion  this is due to moisture getting into the fluid ,,,  clutch and brake fluid collect moisture like a sponge and this causes corrosion   in other words keep all the rubber boots in good order   ( you fit boots around your cv joints to keep the crap out)   , so fit boots around the master and slave cylinders to keep moisture out

[baldric]

these two tools are for inserting the clevis pin  there is a hole drilled down the end of the clevis pin around 1/4"  deep   the clevis pin is pushed on the end of the tool  line the fork up with the clutch pedal   wiggle the pedal around until the pin finds the position  insert split pin   job done    as you can see clevis pin has a hole in the end  the other  wire tool is to help remove split pin  insert the tip in the eye of the split-pin slight pulling pressure whilst straightening the split pin  , with what ever you have at hand

 

 P1020084.jpg   138.5K   6 downloads

 

 

the new and old  cluster bolts  the new one is the longer one  , simply because there has been two new side pads welded to the side of the brake cluster     also a greas nipple had been added to the hex head end for lubricating the pedal bushes  the thread of the greas nipple  is a 1/4"  B.S.F  ,the threaded end  is 5/16  U.N.F.  notice I have stoped the thread a good  1/4"  inch  from the shoulder  and the plain bit before the thread starts   is to rest the nut on  , so a bloke dosent  keep losing the nut  ,,, its called a nut lead  

 

 P1020084.jpg   138.5K   6 downloads

 

the pedal box  cluster  with pedal bolt in place  and half way up the cluster arms  is a spreader  ( its a flimsy box)  painted in a disgustin hamerite green  silly daughter  choice of colour

 

 P1020086.jpg   146.03K   2 downloads

 

left hand side of the pedal cluster  with the pedal bolt in place  greas nipple fitted  and a locking tab welded on to stop the pedal bolt from revolving  with disgusting green paint  ( her choice not mine)

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greas ports for the pedal bushes in the through bolt

 

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close up of the hexhead through ,pedal bolt  showing the welded tab to stop the bolt revolving when the pedal nut is being undone

 

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the original  thru bolt   and the new one  note the threaded end has been stoped  short of the shoulder  also there has been a lead spigot  turned  to rest the fixing nut on  before final  screwing in place  , makes things easier  to start the thread  and less chance of loosing the nut in some aquard  place

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•  P1020085.jpg   155.68K   7 downloads

Edited by baldric, 24 October 2013 - 06:16 AM.

[baldric]

I suppose I got too excited  putting too many images on  and the computer couldent work it out  dam silly thing   just follow the images they are self explaning   when the scribes have been red     ;  ohhhh begger what a mess 

baldric

[Ethel]

The Metro uses the same slave as the Mini, but of course had entirely different pedals. I've got a Metro master pushing my per verto Mini clutch, the bight point is lower, but it works fine. I'm impressed by the grease nipple, haven't seen a pedal box like that on a Mini, maybe it's also off an 1100, it may explain those pushrods???