HJ 47 Dash Brake light always on

[blastr9]

I have a 82 HJ47 and the brake warning light on the dash is always on. The brake fluid level its at the top. Could it be the vacuum form the alternator? If so, what vacuum level should there be?

Is there a way to check the sensor in the cap of the brake fluid resevoir?

Any other obvious things to check?

Thanks,

John

69 FJ40
82 HJ47

 

[amaurer]

Yep, vacuum problem, likely. If its stops OK it might just be the switch - pull the sensor wires off at the vacuum tank and short them to see if you can get the light to go out.

 

[blastr9]

Thanks Amaurer.

 

[lostmarbles]

...Is there a way to check the sensor in the cap of the brake fluid resevoir?....John......82 HJ47

Hi John

If your HJ47 is the same as my BJ40, the LH light is operated ONLY by the brake-fluid-level-switch/device.



And it is easy enough to check.

Your multimeter should show "continuity" (on the ohms setting) only when the lid is removed so (to make the sensor think the reservoir is low).





But Amaurer/Drew could be right and yours may be operated from the low-vacuum switch instead. (On my cruiser that operates an audible alarm.) I think different models and different markets got different wiring here.

Edit (next day)...Actually....from memory....the level device is not strictly speaking a "switch". So rather than talking about "continuity" I should have said it has "high resistance" when detecting normal fluid level and "low resistance" when detecting an abnormally low level. In fact that LH bulb never glows as brightly as the right-hand one because the level-detecting-device always maintains some resistance.

 

[blastr9]

Tom,

Great information. I will test the cap when I get back home in a week.

Thanks,
John

 

[gswest]

I have the same problem on my 47. Let me know how it goes on your's and I'll check mine this week as well. My fluid level is correct and my brakes work OK.

 

[amaurer]

Huh, didn't know that about the older trucks Tom, interesting.

Here is a shot from the owners manual, nothing really new here.

 

[blastr9]

Thanks again Amaurer,

I return back from OZ in about a week and will sort out the issues. I am trying to find a replacement cap for the brake reservoir just in case.

 

[amazon196969]

Blastr9...did you end up finding a replacement cap for the brake reservoir??

 

[amazon196969]

Blastr9...did you end up finding a replacement cap for the brake reservoir??

 

[amazon196969]

Hi lostmarbles Tom,
Awfully sorry to hear of your loss and hope most was salvageable, water wells in my eyes every time I read it...just checking out your image of your reservoir set-up above which looks the same as mine, although yours looks in much better nick and seems mine is not what it should be as it seems PO has lost or damaged the float and I assume snipped the wire to disarm the dash light...out of curiosity did you purchase this and fit it yourself or did it come with the vehicle???I am trying to chase the sensor and float part with wires and connector but can't seem to find any where I am looking (BIG negative of living in Oz)...had 2 goes with Toyota direct yesterday who have given me 2 part numbers to try so far, the 1st was for the cap and the 2nd was for a pressure switch...the guy I was talking to sounded like he knew what I was talking about form the very beginning, as he asked if it was the bit that sits in the lid with 2 wires etc and I agreed that that was the part I was chasing, but still hasn't come up with the right part #...he sent me a diagram with parts in the image, but the part I need is labeled as the cap with no mention of the sensor...can you or anyone send some light my way on where I would purchase?? My next option is Facebook groups to see if anyone has any spares but would prefer new...
cheers
Kylie