![]() |
|
Porsche, and the Porsche crest are registered trademarks of Dr. Ing. h.c. F. Porsche AG.
This site is not affiliated with Porsche in any way. Its only purpose is to provide an online forum for car enthusiasts. All other trademarks are property of their respective owners. |
|
![]() |
bbrock |
![]()
Post
#1
|
914 Guru ![]() ![]() ![]() ![]() ![]() Group: Members Posts: 5,269 Joined: 17-February 17 From: Montana Member No.: 20,845 Region Association: Rocky Mountains ![]() ![]() |
I just finished rebuilding my brake regulator with the PMB DIY rebuild kit and it looks like new. Only thing left is to set the switch to 525 psi. I'm guessing I could send it to PMB to have them set it, but wondering if this could be done locally at a brake shop. Anyone know?
|
![]() ![]() |
Superhawk996 |
![]()
Post
#2
|
914 Guru ![]() ![]() ![]() ![]() ![]() Group: Members Posts: 6,029 Joined: 25-August 18 From: Woods of N. Idaho Member No.: 22,428 Region Association: Galt's Gulch ![]() ![]() |
Any pic of the internals and the valve assembly in the manual or from when you rebuilt yours?
I've been curious about whats in the "box" and thought about disassembling mine before sending. That lasted about a minute before I concluded I need to focus on the more important structural repairs. (IMG:style_emoticons/default/welder.gif) Most proportioning valves in old school cars and trucks (i.e. pre-ABS) are set up such that they build a pressure at a fixed rate (gradient) in proportion to the fronts and then they level out at a set pressure and then flat line at that pressure. In a sedan this is usually set so the rear brakes don't lock up in a light load condition once weight is transferred to the front axle under braking. There are other versions with mechanical linkages to try to vary that proportioning relative to load and/or body position. Example I have a MotoGuzzi that changes rear proportioning when a rider or heavy load is on back of the bike. Many trucks ran setups like this to account for the big swing between driver only and max Gross Vehicle Weight (GVW) with payload and trailers. I assume the 914 valve is doing something similar but since the vehicle doesn't have a big weight delta between light load (i.e. driver only) and GVW at 2 passengers + luggage it is probably less "conservative" in that gradient is steeper and the 525 psi max limit is very plausible to keep from locking the rears. However, back to your point most proportioning valves really aren't a rebuildable affair on any modern (say late 70's to mid 90's) vehicles. I certainly haven't seen everything that is out there but in my experience the 914 valve is a bit unique in that its adjustable outside of the plant. Most that I've seen in mass production are just a check valve set via spring forces and orifice size at the time of manufacture. |
![]() ![]() |
![]() |
Lo-Fi Version | Time is now: 1st July 2024 - 12:34 AM |
All rights reserved 914World.com © since 2002 |
914World.com is the fastest growing online 914 community! We have it all, classifieds, events, forums, vendors, parts, autocross, racing, technical articles, events calendar, newsletter, restoration, gallery, archives, history and more for your Porsche 914 ... |