I have been reading a few other threads but nothing seems to be very definitive so I would like some opinions on whether I am going after the right thing.
Truck:
1993 FZJ80 with a 1HDT swapped, engine and tranny are at 200,000km, everything else is at around 700,000km's. Was daily driven but has been side lined and only drive 1 day a year but mainly sitting outside
Symptoms:
I noticed that it seemed to be getting hard to hit the brakes, I can hit the brakes as hard as I can but I can't lock up the tires on dry pavement (ABS Disabled).
I was pulling 1/2 yard of topsoil and went to hit the brakes but could barely stop.
With the truck running I can stand on the brakes and I feel them slowly moving towards the floor over time.
With the truck running I hit the brakes hard three times, on the third time the brake light comes on.
When driving I can hit the brakes hard once, on the second pump they feel very firm and don't seem as effective.
Maintenance Completed:
Brake pads were replaced a few thousand km's ago
I replaced all the soft lines
Replaced load sensing valve about a year ago
Replaced master cylinder with one from Cruiser Teq (AISIN) thinking this was causing pedal drift.
Brake system was fully bled twice with a power bleeder. Trigger the ABS on a gravel road a few times and cracked the lines while the system was under pressure to vent all the air.
Tests completed:
With the truck off they seem very hard and don't drift.
With the truck off I can pump the brakes until they get hard, holding pressure on the pedal I turn on the engine and the brake pedal drifts down about 3"
Keeping my foot on the brake I shut the truck off and the pedal stays down and does not seem to force the pedal back up after about 1 minute of waiting.
The truck was running and then shut off for about an hour, when I pulled off the vacuum B I could hear a hiss, and then when I removed hose D I heard another hiss.
Using a small vacuum hand pump I found the following
System holds vacuum when drawing 20inhg in locations D, B, C. Let it sit for 3 minutes at each location. No gauge drift.
Check valve C seems to be working, I can draw vacuum but I can't blow back into the system (using my mouth) - SHOULD I TEST THIS ANOTHER WAY?
With hose D connected back to A I can draw vacuum on B and it all holds
Connecting gauge at D and B and then starting the engine shows 28inhg
Opinions needed
I'm thinking my booster might have an internal problem: Thoughts?
My other thought was that I had a leaking caliper or seized caliper but my thoughts are that would simple be a squishy pedal situation.
Please let me know your thoughts, I don't want to just keep throwing parts at it.
Cheers,
Rob
Truck:
1993 FZJ80 with a 1HDT swapped, engine and tranny are at 200,000km, everything else is at around 700,000km's. Was daily driven but has been side lined and only drive 1 day a year but mainly sitting outside
Symptoms:
I noticed that it seemed to be getting hard to hit the brakes, I can hit the brakes as hard as I can but I can't lock up the tires on dry pavement (ABS Disabled).
I was pulling 1/2 yard of topsoil and went to hit the brakes but could barely stop.
With the truck running I can stand on the brakes and I feel them slowly moving towards the floor over time.
With the truck running I hit the brakes hard three times, on the third time the brake light comes on.
When driving I can hit the brakes hard once, on the second pump they feel very firm and don't seem as effective.
Maintenance Completed:
Brake pads were replaced a few thousand km's ago
I replaced all the soft lines
Replaced load sensing valve about a year ago
Replaced master cylinder with one from Cruiser Teq (AISIN) thinking this was causing pedal drift.
Brake system was fully bled twice with a power bleeder. Trigger the ABS on a gravel road a few times and cracked the lines while the system was under pressure to vent all the air.
Tests completed:
With the truck off they seem very hard and don't drift.
With the truck off I can pump the brakes until they get hard, holding pressure on the pedal I turn on the engine and the brake pedal drifts down about 3"
Keeping my foot on the brake I shut the truck off and the pedal stays down and does not seem to force the pedal back up after about 1 minute of waiting.
The truck was running and then shut off for about an hour, when I pulled off the vacuum B I could hear a hiss, and then when I removed hose D I heard another hiss.
Using a small vacuum hand pump I found the following
System holds vacuum when drawing 20inhg in locations D, B, C. Let it sit for 3 minutes at each location. No gauge drift.
Check valve C seems to be working, I can draw vacuum but I can't blow back into the system (using my mouth) - SHOULD I TEST THIS ANOTHER WAY?
With hose D connected back to A I can draw vacuum on B and it all holds
Connecting gauge at D and B and then starting the engine shows 28inhg
Opinions needed
I'm thinking my booster might have an internal problem: Thoughts?
My other thought was that I had a leaking caliper or seized caliper but my thoughts are that would simple be a squishy pedal situation.
Please let me know your thoughts, I don't want to just keep throwing parts at it.
Cheers,
Rob
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