International Full Size Jeep Association
Home Forums Reader's Rigs Tech Library Trail Stories FSJ-List
International Full Size Jeep Association  

Go Back   International Full Size Jeep Association > Tire Kickin' > Diesel Swaps

Reply
 
Thread Tools Search this Thread Display Modes
  #21  
Old 03-30-2013, 07:06 AM
Elliott's Avatar
Elliott Elliott is offline
Cowboy Up
 
Join Date: Jun 22, 2002
Location: Pilot Point, TX
Posts: 12,704
Quote:
Originally Posted by poolmike
Been cruising in my M715 for 5 years with Hydroboost out of a '86 Chevy K30 donor truck. It worked great or so I thought....yesterday I swapped in a 4 wheel disc master cylinder from a '03 Silverado 3500 with a Wilwood adjustable prop valve. What a difference. If I get into the brake pedal, my seatbelt better be fastened or I'll be eating the windshield.

That's stepping up to 37mm bore which is 1.45" vs the 1.25" bore you had and it was designed for the largest dual piston calipers they make for light trucks. The stub on that MC should have been too large (at ~1.8") to fit into the bore (~1.63") of the '86 HB though.... it fit? or did you build an adapter and rotate the HB?
__________________
*** I am collecting pics and info on any factory Jeep Dually trucks from the J-Series at the new Jeep Dually Registry.
***I can set you up with hydroboost for your brakes: http://www.ifsja.org/forums/vb/showthread.php?t=106056
Reply With Quote
  #22  
Old 03-30-2013, 11:02 AM
Iceman0502's Avatar
Iceman0502 Iceman0502 is offline
Member
 
Join Date: Oct 27, 2010
Location: Long Island, New York
Posts: 55
Thanks for vclarifying all those items. The spacer is really used to match the length of the rod becuase its not smart to weld on the rod becuase it melts the seal.

Car craft had a article once and the welded a rod, but never mentioned to be careful of the seal.

Just thinking out loud, but instead of adding a spacer on the HB side, are you able to move the mounting location on the pedal side. i havent looked at one in while, but could you weld a tab on the pedal one inch closer to the driver and drive a new hole? Would this throw off the travel of the HB?
I read somewhere that Chevy trucks have a brake pedal for the hydro vs vacum boost. It said the pedal would be much higher if you used HB on a vacum pedal.
__________________
1982 Wagoneer - 12V Cummins - In Progress
Reply With Quote
  #23  
Old 03-30-2013, 11:31 PM
SJTD SJTD is offline
350 Buick
 
Join Date: Apr 26, 2012
Location: Lompoc and Sunland, CA
Posts: 1,382
The pedal looks cast to me. I didn't trust welding it. I made a link that moved the pin to the back of the pedal and put the rod on the left side.

This allowed a mount on the front of the firewall 1" thick and moved it about 1-1/2" to the left. My TC is on the left and was too close to the accumulator.

It's from a 2006 Chevy. I did shorten the rod but the weld is near the pedal end and I kept the seal area cold.
__________________
Sic friatur crustulum

'84 GW with Nissan SD33T, early Chev NV4500, 300, narrowed Ford reverse 44, narrowed Ford 60, SOA/reversed shackle in fornt, lowered mount/flipped shackle in rear.
Reply With Quote
  #24  
Old 03-31-2013, 07:23 AM
Elliott's Avatar
Elliott Elliott is offline
Cowboy Up
 
Join Date: Jun 22, 2002
Location: Pilot Point, TX
Posts: 12,704
Quote:
Originally Posted by Iceman0502
Thanks for vclarifying all those items. The spacer is really used to match the length of the rod becuase its not smart to weld on the rod becuase it melts the seal.

Right, and old seals will handle even less heat. With the Astro HB you have a flat mounting plate so you can simply invert the HB to move the accumulator away from the engine. If you use a different HB I have Astro repro mounting plates on ebay or you can pull one in a yard and then cut/thread the brake rod 3/8-24 for coupling to a shortened rod. Just steer away from the GM truck HBs that have a stepped down rod diameter ~1.5" from the back of the HB casting as you can't thread up that section.

If try to go too short without a spacer you increase the brake rod angle unless you are redrilling the firewall bolt pattern and enlarging the center hole... just extra work over making a 1" spacer and using the aluminum block with the correct 6* angle built in.

What ever HB/rod you use don't put yourself in a situation with the overall rod length where you have to thread further towards the HB casting than the width of a pair of vise grips as any jamb nut up beyond that will strike the casting of the HB before you get full pedal articulation so you shorten the stroke on your MC.
__________________
*** I am collecting pics and info on any factory Jeep Dually trucks from the J-Series at the new Jeep Dually Registry.
***I can set you up with hydroboost for your brakes: http://www.ifsja.org/forums/vb/showthread.php?t=106056
Reply With Quote
  #25  
Old 04-02-2013, 09:30 PM
poolmike poolmike is offline
Member
 
Join Date: Mar 03, 2005
Location: Richboro, PA
Posts: 134
Quote:
Originally Posted by Elliott
That's stepping up to 37mm bore which is 1.45" vs the 1.25" bore you had and it was designed for the largest dual piston calipers they make for light trucks. The stub on that MC should have been too large (at ~1.8") to fit into the bore (~1.63") of the '86 HB though.... it fit? or did you build an adapter and rotate the HB?


I rotated the HB when I swapped in the 12 valve. The new master cylinder is a snug fit in the HB, but it went in. Maybe the previous owner of the donor truck swapped in a later model HB? Most of the later model HB's have a shorter pushrod, this one is not. Makes me wonder what it is? Whatever it is, stops the truck!
__________________
'68 M715, Cummins P-pump 5.9, NV4500, NP205, 14 bolt/Dana 60, 20x10 American Racing Mojave's w/12.50R20 Michelin XL's, relentless rust....
Reply With Quote
  #26  
Old 05-04-2013, 08:09 PM
Iceman0502's Avatar
Iceman0502 Iceman0502 is offline
Member
 
Join Date: Oct 27, 2010
Location: Long Island, New York
Posts: 55
So this is going to sound stupid, but I will a master cylinder from a 94 dodge ram 2500 work with a Astro van hydroboost.

I'm asking because my donor truck was a 2500 a the mc fits on the booster, but how do I know if whole combination works. The ram 2500 mc should should be equivalent to a Chevy 2500. There are both 1.25" bores.

Does it make sense to use the Ram proportional valve that is attached to the mc? same disc/drum application?

Thanks
__________________
1982 Wagoneer - 12V Cummins - In Progress

Last edited by Iceman0502 : 05-06-2013 at 12:48 PM.
Reply With Quote
  #27  
Old 05-08-2013, 04:22 AM
poolmike poolmike is offline
Member
 
Join Date: Mar 03, 2005
Location: Richboro, PA
Posts: 134
The two units will probably bolt together and work. An adjustable prop valve will be your best bet.
__________________
'68 M715, Cummins P-pump 5.9, NV4500, NP205, 14 bolt/Dana 60, 20x10 American Racing Mojave's w/12.50R20 Michelin XL's, relentless rust....
Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Running Hydro Assist Steering and Hydroboost...lets talk Michael Off-Road FSJ Tech 72 01-21-2011 09:43 PM
brake problems...help!!!! disc/disc hydroboost setup quikclimber Off-Road FSJ Tech 16 10-04-2008 10:16 AM
Grr, need some hydroboost clarification DanHS General FSJ Tech 9 05-05-2007 09:27 PM
El Dorado Hydraboost Hydroboost want to get my facts straight dusty General FSJ Tech 10 03-04-2007 07:13 PM


All times are GMT -6. The time now is 06:52 AM.


Powered by vBulletin Version 3.5.4
Copyright ©2000 - 2020, Jelsoft Enterprises Ltd.
corner corner