- Posts: 3256
- Thank you received: 2011
PBR park brake valve.
10 months 1 week ago #251370
by JOHN.K.
Replied by JOHN.K. on topic PBR park brake valve.
Is there a line direct to the compressor?.......that would be most unusual...........all the lines should be from the second air tank ,except the one from the maxi release tank.
Please Log in to join the conversation.
10 months 1 week ago #251390
by asw120
“I offer my opponents a bargain: if they will stop telling lies about us, I will stop telling the truth about them”
― Adlai E. Stevenson II
Replied by asw120 on topic PBR park brake valve.
I don't know the purpose of the two lines. Air comes out of both at about the same amount immediately on startup. I can't imagine why it would need two of the same feed. Valve inlets are marked "supply" and "tank".
Jarrod.
Jarrod.
“I offer my opponents a bargain: if they will stop telling lies about us, I will stop telling the truth about them”
― Adlai E. Stevenson II
Please Log in to join the conversation.
Less
More
- Posts: 908
- Thank you received: 748
10 months 1 week ago #251392
by 180wannabe
Replied by 180wannabe on topic PBR park brake valve.
My guess is that one feed is from an air tank that builds pressure equally with the whole system, and so in normal driving the brakes will only release when the whole system is up to pressure. I am guessing the other feed is from a single specific tank to allow for "emergency" release.
So, in standard use the T handle is pulled out for release, in emergency the T handle is held in for release, and so i am guessing the valve admits feed from the appropriate tank depending which way the handle is operated.
Again, i'm only guessing, but that's my take on it if it makes any sense.
Brett.
So, in standard use the T handle is pulled out for release, in emergency the T handle is held in for release, and so i am guessing the valve admits feed from the appropriate tank depending which way the handle is operated.
Again, i'm only guessing, but that's my take on it if it makes any sense.
Brett.
The following user(s) said Thank You: asw120, oliver1950
Please Log in to join the conversation.
10 months 1 week ago #251394
by asw120
“I offer my opponents a bargain: if they will stop telling lies about us, I will stop telling the truth about them”
― Adlai E. Stevenson II
Replied by asw120 on topic PBR park brake valve.
It does make sense, thanks. I will have to get underneath to see if it's even possible to follow the lines. This thing has tanks everywhere.
Jarrod.
Jarrod.
“I offer my opponents a bargain: if they will stop telling lies about us, I will stop telling the truth about them”
― Adlai E. Stevenson II
The following user(s) said Thank You: 180wannabe, cobbadog
Please Log in to join the conversation.
Less
More
- Posts: 908
- Thank you received: 748
10 months 1 week ago - 10 months 1 week ago #251399
by 180wannabe
Replied by 180wannabe on topic PBR park brake valve.
Jarrod, i guess i have concentrated on following the CA282 path with you to keep what you have original and working, but thinking further, in all honesty i reckon John.K's suggestion of a PP1 valve would be adequate, cheap, and easy, unless something/some law, or rule book, specifically states that you need the combination emergency release function.
I can't see an issue in blocking off the feed from which ever tank is not required for the PP1, or..................., joining both feeds together before they enter the PP1, although that might? mess up the low pressure "pop" application (at around 40psi), i don't know for sure, but it think it might.
I don't recall our L9000 Ford, or the T400 KW having an "emergency" release feature, and the old G88 we still have certainly doesn't. The Mk2 Atkinson does, but the Mk3 doesn't. Both my A series ACCO trucks do, however both my later C series ACCO's don"t. And our Hino GT 4x4 doesn't.
If there are no rules actually requiring the emergency release feature, the PP1 certainly looks like a good option, or perhaps a Sealco equivalent.
Just thinking out loud.
Brett.
I can't see an issue in blocking off the feed from which ever tank is not required for the PP1, or..................., joining both feeds together before they enter the PP1, although that might? mess up the low pressure "pop" application (at around 40psi), i don't know for sure, but it think it might.
I don't recall our L9000 Ford, or the T400 KW having an "emergency" release feature, and the old G88 we still have certainly doesn't. The Mk2 Atkinson does, but the Mk3 doesn't. Both my A series ACCO trucks do, however both my later C series ACCO's don"t. And our Hino GT 4x4 doesn't.
If there are no rules actually requiring the emergency release feature, the PP1 certainly looks like a good option, or perhaps a Sealco equivalent.
Just thinking out loud.
Brett.
Last edit: 10 months 1 week ago by 180wannabe. Reason: add detail
Please Log in to join the conversation.
10 months 1 week ago #251404
by wee-allis
Replied by wee-allis on topic PBR park brake valve.
Trucks built with a single circuit air brake system and fitted with spring brakes, (Maxis), were required to have an emergency brake release under the ARD's current at the time. Once the duaL system came into being, it was no longer required.
Had a customer with a LNT which was built at the time of the change over which had both dual circuit system and an emergency release button. Idiot inspector knocked it back because the button didn't work. He couldn't be convinced, so after consultation with RTA head office that the release was not required, I removed the knob on the button and all was good
Had a customer with a LNT which was built at the time of the change over which had both dual circuit system and an emergency release button. Idiot inspector knocked it back because the button didn't work. He couldn't be convinced, so after consultation with RTA head office that the release was not required, I removed the knob on the button and all was good
Please Log in to join the conversation.
10 months 1 week ago #251432
by jon_d
Replied by jon_d on topic PBR park brake valve.
Hi Jarrod,
I've scanned 2 brake set ups from the Bedford bus brake manual. The use different 3 port valves, however, the concept may be the same as yours. And it explains a little about the park brake mechanism.
hope this helps. jd
I've scanned 2 brake set ups from the Bedford bus brake manual. The use different 3 port valves, however, the concept may be the same as yours. And it explains a little about the park brake mechanism.
hope this helps. jd
Please Log in to join the conversation.
10 months 1 week ago #251433
by JOHN.K.
Replied by JOHN.K. on topic PBR park brake valve.
You can ignore any pommy stuff ..its all stupid complicated .......at one time the poms had triple diaphragm brakes on every wheel.........alls needed for an old bus is a single line to the two spring chambers from the PP1 ,and a single line from an air tank to the PP1...........just so the maxis set when the button is pulled out ,release when its pushed in,and the button pops out at around 60psi falling pressure..............even with no valve ,the maxis will slowly come on as pressure in the system falls.
Please Log in to join the conversation.
10 months 1 week ago #251434
by asw120
“I offer my opponents a bargain: if they will stop telling lies about us, I will stop telling the truth about them”
― Adlai E. Stevenson II
Replied by asw120 on topic PBR park brake valve.
“I offer my opponents a bargain: if they will stop telling lies about us, I will stop telling the truth about them”
― Adlai E. Stevenson II
Please Log in to join the conversation.
Time to create page: 0.557 seconds