Labor Day Putting down your wrenches or time for
MORE wrenching? 
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| | | | Joined: Jan 2007 Posts: 117 Shop Shark | | Shop Shark Joined: Jan 2007 Posts: 117 | what is the sockit size on the master cylinder on a 47-54 pickup ?? can any buddy help me out ?
care to chat write back
| | | | | Joined: Feb 2008 Posts: 212 'Bolter | | 'Bolter Joined: Feb 2008 Posts: 212 | I have a 58 3100 and mine is sort of rounded off but I used a 4 way lug wrench to take mine on and off. Give it a try. | | | | | Joined: Feb 2004 Posts: 29,742 Kettle Custodian (pot stirrer) | | Kettle Custodian (pot stirrer) Joined: Feb 2004 Posts: 29,742 | Are you referring to the big nut that retains the piston and spring assembly? I believe it's 1 3/8". A flat-ended punch against a corner of the nut and a vigorous whack with a BFH is the way we loosened that nut back when I was making a living working on them. We virtually never removed a master cylinder to rebuild it, just change out the internals with the M/C mounted on the frame!
Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!
| | | | | Joined: Jan 2007 Posts: 117 Shop Shark | | Shop Shark Joined: Jan 2007 Posts: 117 |
care to chat write back
| | | | | Joined: Apr 2008 Posts: 899 'Bolter | | 'Bolter Joined: Apr 2008 Posts: 899 | Jerry, that explains the cut in the nut on my master cylinder. Thought it was from a pipe wrench. Never would've guessed a punch.
Last edited by Forty9; 05/22/2012 6:20 PM. Reason: more info
Ed
| | | | | Joined: Jun 2011 Posts: 5,096 Crusing in the Passing Lane | | Crusing in the Passing Lane Joined: Jun 2011 Posts: 5,096 | Perhaps you are referring to the filler cap-could be 8 point, use a large Cresent wrench,(they make metric ones now) etc., or find the correct size, measure across the flats, count the flats, remember, you, or someone else(your kid) might have to do this in the future, rounded off fasteners don't help the issue.
'37 GMC T-18 w/ DD 4-53T, RTO-610, 6231 aux., '95 GMC running gear, full disc brakes, power steering, 22.5 wheels and tires.
'47 GMC 1 ton w/ 302, NP-540, 4wd, full width Blazer front axle.
'54 GMC 630 w/ 503 gasser, 5 speed, ex fire truck, shortened WB 4', install 8' bed.
'55 GMC 370 w/270, 420 4 speed, grain, dump bed truck from ND. Works OK.
| | | | | Joined: Feb 2004 Posts: 29,742 Kettle Custodian (pot stirrer) | | Kettle Custodian (pot stirrer) Joined: Feb 2004 Posts: 29,742 | How many of these master cylinders have you rebuilt?
Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!
| | | | | Joined: Apr 2005 Posts: 926 Shop Shark | | Shop Shark Joined: Apr 2005 Posts: 926 | For the filler caps,a faucet wrench works pretty nice. If it's so tight you bugger it up removing it,it needed replacement anyway. I use an O-ring instead of a gasket so it only has to be finger-tight to seal.
Speed | | | | | Joined: Nov 2001 Posts: 1,517 'Bolter | | 'Bolter Joined: Nov 2001 Posts: 1,517 | Ive always used Jerrys method for re-building them in the vehicle.
For the top filler nut, a crescent wrench on end, with a screwdriver stuch thru the hole and ,,,,twist. | | |
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