× A place for more technical discussions. Please make sure you post in the correct section on the site, this way it keeps the site tidy AND ensures you get a more relevant answer.

Front Hub Vacuum Route ?

More
22 Jul 2019 15:33 #211404 by Velocette
I think that I have a blockage somewhere in the front hub vacuum system,,not the pipes,,and wondered if anyone has a detailed diagram of the exact route of the locking and unlocking passageways so that I can clean things out. If I has access to an airline I would just blast them through but alas its hand tools only. Any ideas ?

Please Log in or Create an account to join the conversation.

More
23 Jul 2019 08:41 #211420 by zukebob
Replied by zukebob on topic Front Hub Vacuum Route ?
I don't know if this is as detailed as you want.

Do you have a push-button transfer?

I started out with nothing & still have most of it left
Attachments:

Please Log in or Create an account to join the conversation.

More
23 Jul 2019 09:27 - 23 Jul 2019 09:28 #211422 by Velocette
Replied by Velocette on topic Front Hub Vacuum Route ?
Thanks for that,,its a far better image than I have seen so far but it still just shows the pipes disappearing behind that hub plate. I'm wanting to see the exact passageway that each vacuum pipe takes through the hub/mechanism to lock and unlock it. It may seem a bit pedantic but I know what it does and now I want to know how it does it ! Thanks again. PS. its a push button system.
Last edit: 23 Jul 2019 09:28 by Velocette. Reason: Missed a bit.

Please Log in or Create an account to join the conversation.

More
23 Jul 2019 22:49 #211435 by yakuza
Replied by yakuza on topic Front Hub Vacuum Route ?
I would love to help as I suspect the normal solution to just switch to manual hubs is at best a bit hasty. The vacuum hubs have a bad reputation but very seldom I see someone like you who wants to fix them.
I love my vacuum hubs. Had manual on my previous cars and I often did forget to switch them over..
It is like the SJ413 carb that everyone says to replace, but it is serviceable..
Have you had a look in the FSM for the hubs?

2005 Jimny M16A VVT, 235 BFG MT, 2" Trailmaster, 17%/87% high/low gears.

Please Log in or Create an account to join the conversation.

More
24 Jul 2019 01:39 - 24 Jul 2019 01:40 #211438 by zukebob
Replied by zukebob on topic Front Hub Vacuum Route ?
The reason I wanted to know if it was a push button transfer is so that I could ask a follow-on question.

Someone can correct me if I am wrong but I believe if there is a blockage in the lines to the hubs, your hubs wouldn't engage but the transfer would engage successfully (the controller would still see a vacuum). When you push the 4WD button does the transfer engage or do you have flashing lights? I'm thinking that if you have flashing dash lights, you more likely have a vacuum leak.

I started out with nothing & still have most of it left
Last edit: 24 Jul 2019 01:40 by zukebob.

Please Log in or Create an account to join the conversation.

More
24 Jul 2019 11:02 #211441 by bryn
Replied by bryn on topic Front Hub Vacuum Route ?
Once you press the 4xd button, the transfer box engages the drive shaft to the front wheels and the vacuum hubs engage the wheels to the drive shaft. You can have a situation whereby the hubs do not engage or only one engages and the dash light will show you in 4xd. The way I check is to take off the hubs and see which has engaged. Its also worth carrying a hex socket and wrench for that purpose to get you out of trouble.
Flashing lights can indicate a transfer box problem; there’s a couple of solenoid switches on the transfer box where the wires get pulled out as happened to me or a problem with the vacuum.
If you go over to manual hubs then you block the pipes to make the system function so having blockage will have the same effect ie no flashing lights.
These are my experiences of the system which can be very frustrating however there are chaps on here who are far more experienced than me who should be able to put you right.
Good luck
bryn

Please Log in or Create an account to join the conversation.

More
24 Jul 2019 20:25 #211450 by Velocette
Replied by Velocette on topic Front Hub Vacuum Route ?
Thanks for all the good advice. I had another look today and found that if I clamp off the rubber vacuum pipes just below the bulkhead,,where the metal pipes from the solenoids end and press the 4x4 button then the transfer box engages correctly. If I then clamp off each pair of vacuum pipes,one pair at a time,,I found that with the offside clamped, pressing the 4X4 button engaged the transfer box and locked the nearside hub giving me a constant green light on the dash. When I reversed this to the nearside pipes clamped I got the dreaded flashing green light. I did the clamping as near as possible to the plastic T piece which diverts vacuum to each hub. I,ve got a few yards of new silicon rubber tube coming so intend to replace the lot to be sure that there is no problem there. My car has rubber tube right the way across the front axle so no corroded metal pipes for me ! Whilst looking at the O/S hub I found that the wheel bearing to be a bit slack so I,ll replace that and have a thorough look at vacuum routes at the same time,,and if possible,,take pictures of the result and put them on here.

Please Log in or Create an account to join the conversation.

  • Lambert
  • Lambert's Avatar
  • Offline
  • Moderator
  • Moderator
    Registered
  • The quickest Jimny in Harrogate...(that I own)
More
25 Jul 2019 04:16 #211454 by Lambert
Replied by Lambert on topic Front Hub Vacuum Route ?
If you have a slack wheel bearing it is possible that the vacuum is leaking from the hub nut flangeas it is the running surface for the hub seal. Any miss alignment is undesirable.

Dreadnaught (black 2011)

Please Log in or Create an account to join the conversation.

More
25 Jul 2019 10:39 #211458 by Velocette
Replied by Velocette on topic Front Hub Vacuum Route ?
Just what I am starting to think,,so I've a bearing kit with seals etc to belt and brace the job. As an aside,,I was in a particularly claggy field close to Harrogate when it decided to play up yet with very road type tyres and no 4X4 the car just sailed through it all without a twitch !!

Please Log in or Create an account to join the conversation.

More
25 Jul 2019 17:06 #211464 by bryn
Replied by bryn on topic Front Hub Vacuum Route ?
Id be very interested to observe/give you a hand replacing the front wheel baring as I think one of mine my need doing at some point. Ive replace the king pin barings many times so I would be hopefully more than a hindrance.
I live near harrogate.

Regards
bryn

Please Log in or Create an account to join the conversation.

More
25 Jul 2019 19:12 #211466 by Velocette
Replied by Velocette on topic Front Hub Vacuum Route ?
That's a welcome offer,,I'll give you a call tomorrow from my black jimny that's full of pigeons !!

Please Log in or Create an account to join the conversation.

  • Lambert
  • Lambert's Avatar
  • Offline
  • Moderator
  • Moderator
    Registered
  • The quickest Jimny in Harrogate...(that I own)
More
25 Jul 2019 19:34 #211467 by Lambert
Replied by Lambert on topic Front Hub Vacuum Route ?
Ooooh a harrogate massive! We'll have to have a meet to compare and contrast Jimny mods!

Dreadnaught (black 2011)

Please Log in or Create an account to join the conversation.

Time to create page: 0.148 seconds
Powered by Kunena Forum

I hope you enjoy using this forum. Please consider making a donation towards the upkeep of this forum website.