BJ46 searching for a load sensing proportioning valve (1 Viewer)

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

Joined
Feb 16, 2021
Threads
5
Messages
31
Location
CH
Hi all

In vain, I've been searching around the rear axle for a load sensing proportioning valve in my 1983 BJ46 (JDM).
The reason is that my rear brakes (drum) tend to lock up when braking abruptly and I got the hint that maybe the LSPV needs to be adjusted.

In the handbook I have it is depicted to be mounted on the rear axle but now I'm now asking myself...
  • Do not all models of BJ4... have such a valve - was this not stock?
  • Does only my MWB cruiser not have one / could it be that the PO removed it for some reason?
  • If indeed I don't have such a valve, do you guys recommend to fit one - are they even available?
If anybody has some insight regarding the points above that would be great.
Also if this has been discussed in another thread, please point me to it (I was unable to find the answers to my questions so far).
 
Hi all

In vain, I've been searching around the rear axle for a load sensing proportioning valve in my 1983 BJ46 (JDM).
The reason is that my rear brakes (drum) tend to lock up when braking abruptly and I got the hint that maybe the LSPV needs to be adjusted.

In the handbook I have it is depicted to be mounted on the rear axle but now I'm now asking myself...
  • Do not all models of BJ4... have such a valve - was this not stock?
  • Does only my MWB cruiser not have one / could it be that the PO removed it for some reason?
  • If indeed I don't have such a valve, do you guys recommend to fit one - are they even available?
If anybody has some insight regarding the points above that would be great.
Also if this has been discussed in another thread, please point me to it (I was unable to find the answers to my questions so far).
Coincidentally I am in the same position with an ‘84 BJ46. NFI where to find a proportionING valve, my brakes went 2 days ago.

In the wet it was really easy to lock up the rear. Yesterday coming down a hill I went to hit the brakes and the pedal had about 100mm more play before any feedback, then I had to almost put my foot through the floor to get it to stop. Then I had to change my nappy.

The pedal is back to where it used to engage, but feels hard and braking isn’t what it used to be. The rear left drum seems to still be partially engaged because it’s warm...

Anyone have a bush mechanic idea on what might be going on before I go chasing unobtainium parts?
 
I do not have one on either of my BJ46's , I have them on my other Cruisers just not on the BJ46. If you look at the factory lines you will see they go from rear diff housing to chassis is into hard line up to front. If it had one then it would need to be in that location and have a lever to rear axle.
2019-11-09 23.52.48.jpg
 
Thanks for the pic and info @BarnFab.
Do you notice a strong difference in the braking behaviour (esp. regarding likelihood of skidding in the back when braking hard) in these cruisers without the valve versus your cruisers which have one?
Would you consider implementing one / do you know if such valve systems are available somewhere?
 
Thanks for the pic and info @BarnFab.
Do you notice a strong difference in the braking behaviour (esp. regarding likelihood of skidding in the back when braking hard) in these cruisers without the valve versus your cruisers which have one?
Would you consider implementing one / do you know if such valve systems are available somewhere?

Hi, I lock up all 4 at once never had an issue stopping. I would not bother putting one on and see little value in a SWB / MWB 40 as they simply don't move enough to impact it even with a load.

If you have real issues I would look at your M/C first and then if need be wack a 2PSI static pressure valve in the line or buy an adjustable from Summit and play with it, for example ( Brake Proportioning Valves and Distribution Blocks | Summit Racing - https://www.summitracing.com/search/part-type/brake-proportioning-valves-and-distribution-blocks?SortBy=Default&SortOrder=Default&gclid=Cj0KCQjw-pCVBhCFARIsAGMxhAf6Ise4EHMaQD8vkDQpt6y4Gq8k4CoFOovAhQ39d-jeLYv6MvKB0W8aArs4EALw_wcB)

Based on what you are saying I would be looking at your brake system as a whole and starting with your front discs as tehy shoudl sit the 46 on its nose before the rears lock up.
 
Depending on how original you want to keep it, you can always play with the rear wheel cylinder bore sizes to slow down the engagement of the rear shoes, just like Toyota did with the 45 vs 40 rear wheel cylinders
 

Users who are viewing this thread

Back
Top Bottom