hi
1// Assuming vehicle brakes are in good condition
2/ brake controller Earlier Primus models did not come with boost function WHICH IS HIGHLY RECOMENDED
eg Later Primus models
P2 Prodigy have boost also
P3 have boost as well
Boost functions come in 4 levels B,, B1 B2 B3 and not available in other brands eg Redarc
3/ brake wiring single brake axle
both positive should be 4.5 mmsq cable and earth 4.5sqmm cable
both +/- should run back to vehicle battery with only trailer plug connection
4/ brake linnings /drum can come in different compounds soft thru hard etc
brake linnings go very hard if overheated
hard linnings are not for caravans
5/ tyre diameters have a big influence on performance especially 10 inch drum brakes
10 inch struggle to be effective wth big 4x4 diameter wheels anything over 720mm
why big diameter wheels are harder for brakes to operate , brake capacity is reduced
6/ adjust linnings to have a slight rubbing noise evident
wheel should be able to be turned by hand
do not prescribe to adjust then backoff thats for larger hydraulic systems
XTRA drum brake linning clearance will result in late brake application which driver understands as poor braking
Elecmuso said
12:12 PM Aug 7, 2022
Thanks Swamp. The controller is a Tekonsha Primus with boost modes - I have tried all 3 boost modes and none of them result in me being able to set the gain high enough to lock up the caravan brakes when operated manually.
I agree it suggested extra brake lining clearance.
The only reason u tell some one to back off 8--10 clicks is if they have never done brakes b4 ........newbie BUT even so ......
If u back off 8-10 clicks the handbrake would be that far out adjustment it would barely work .
Adjust linnings till slight drag noise is heard where linnings are rubbing against drum ,,wheel should be easy to turn with minor resistance . Done ..
Elecmuso said
05:38 PM Aug 7, 2022
I thought the 8 to 10 clicks would be a bit much as well, and I noticed that one of the comments from the video agrees with you: '8~10 clicks?? For years I've been backing off until just free, then one click.'
Gundog said
09:20 AM Aug 10, 2022
Elecmuso wrote:
Thanks Swamp. The controller is a Tekonsha Primus with boost modes - I have tried all 3 boost modes and none of them result in me being able to set the gain high enough to lock up the caravan brakes when operated manually.
I agree it suggested extra brake lining clearance.
-- Edited by Elecmuso on Sunday 7th of August 2022 12:15:33 PM
-- Edited by Elecmuso on Sunday 7th of August 2022 12:16:12 PM
The boost mode from memory only works with normal braking mode not the manual overide
The Tekonsha P3 has 4 Boost settings B is off is when the trailer is lighter than the tow vehicle but B1 can used , B1 is the factory default setting and and if you caravan is about the weight as the tow vehicle B2 and B can be used, B2 is when the caravan is up to 28% heavier than the tow vehicle B1 and 3 can also be used, B3 is suggested when you caravan is up to 40% heavier than the tow vehicle B2 can also be used.
What the Boost does
With the boost off, during a braking event, the power to the brakes starts out at zero and increases with deceleration.
With the boost on level 1, B1, during a braking event, the power automatically starts out at approximately 13% of the power setting and increases with deceleration.
With the boost on level 2, B2, or with the boost on level 3, B3, during a braking event, the power automatically starts out at approximately 25% of the power setting and increases with deceleration.
In a nutshell its like adjusting the brake bias to have you trailer brakes react a little faster, thus not requiring the front brakes of your tow vehicle do the majority of effort.
INITIAL brake setup important, from Primus manual
Adjusting the Power to the Trailer Brakes (Prior to setting Boost) Once the control has been securely mounted within the -90 to 90 degree range, it is necessary to set the power needed to stop the trailer during a braking event.
1. Connect trailer to tow vehicle.
2. With engine running hold manual full left and set Power Knob to indicate approximately 6.0
3. Drive tow vehicle and trailer on a dry level paved surface at 25 mph and fully apply manual knob.
3 If trailer brakes lock up: q Turn power down using power knob.
3 If braking was not sufficient: q Turn power up using power knob.
4. Repeat Step (3) until power has been set to a point just below wheel lock up or at a sufficient force as to achieve maximum braking power.
5. Using the brake pedal, make a few low speed stops to check the power setting.
-- Edited by Gundog on Wednesday 10th of August 2022 09:30:17 AM
1// Assuming vehicle brakes are in good condition
2/ brake controller Earlier Primus models did not come with boost function WHICH IS HIGHLY RECOMENDED
eg Later Primus models
P2 Prodigy have boost also
P3 have boost as well
Boost functions come in 4 levels B,, B1 B2 B3 and not available in other brands eg Redarc
3/ brake wiring single brake axle
both positive should be 4.5 mmsq cable and earth 4.5sqmm cable
both +/- should run back to vehicle battery with only trailer plug connection
4/ brake linnings /drum can come in different compounds soft thru hard etc
brake linnings go very hard if overheated
hard linnings are not for caravans
5/ tyre diameters have a big influence on performance especially 10 inch drum brakes
10 inch struggle to be effective wth big 4x4 diameter wheels anything over 720mm
why big diameter wheels are harder for brakes to operate , brake capacity is reduced
6/ adjust linnings to have a slight rubbing noise evident
wheel should be able to be turned by hand
do not prescribe to adjust then backoff thats for larger hydraulic systems
XTRA drum brake linning clearance will result in late brake application which driver understands as poor braking
Thanks Swamp. The controller is a Tekonsha Primus with boost modes - I have tried all 3 boost modes and none of them result in me being able to set the gain high enough to lock up the caravan brakes when operated manually.
I agree it suggested extra brake lining clearance.
Interestingly it seems to be a common concern as I have found googling it, for example:
www.jaycoowners.com/forums/f37/trailer-brakes-dont-lock-up-48581.html
-- Edited by Elecmuso on Sunday 7th of August 2022 12:15:33 PM
-- Edited by Elecmuso on Sunday 7th of August 2022 12:16:12 PM
www.youtube.com/watch
This video is so wrong its laughable ...............
The only reason u tell some one to back off 8--10 clicks is if they have never done brakes b4 ........newbie BUT even so ......
If u back off 8-10 clicks the handbrake would be that far out adjustment it would barely work .
Adjust linnings till slight drag noise is heard where linnings are rubbing against drum ,,wheel should be easy to turn with minor resistance . Done ..
I thought the 8 to 10 clicks would be a bit much as well, and I noticed that one of the comments from the video agrees with you: '8~10 clicks?? For years I've been backing off until just free, then one click.'
The boost mode from memory only works with normal braking mode not the manual overide
The Tekonsha P3 has 4 Boost settings B is off is when the trailer is lighter than the tow vehicle but B1 can used , B1 is the factory default setting and and if you caravan is about the weight as the tow vehicle B2 and B can be used, B2 is when the caravan is up to 28% heavier than the tow vehicle B1 and 3 can also be used, B3 is suggested when you caravan is up to 40% heavier than the tow vehicle B2 can also be used.
What the Boost does
With the boost off, during a braking event, the power to the brakes starts out at zero and increases with deceleration.
With the boost on level 1, B1, during a braking event, the power automatically starts out at approximately 13% of the power setting and increases with deceleration.
With the boost on level 2, B2, or with the boost on level 3, B3, during a braking event, the power automatically starts out at approximately 25% of the power setting and increases with deceleration.
In a nutshell its like adjusting the brake bias to have you trailer brakes react a little faster, thus not requiring the front brakes of your tow vehicle do the majority of effort.
INITIAL brake setup important, from Primus manual
Adjusting the Power to the Trailer Brakes (Prior to setting Boost) Once the control has been securely mounted within the -90 to 90 degree range, it is necessary to set the power needed to stop the trailer during a braking event.
1. Connect trailer to tow vehicle.
2. With engine running hold manual full left and set Power Knob to indicate approximately 6.0
3. Drive tow vehicle and trailer on a dry level paved surface at 25 mph and fully apply manual knob.
3 If trailer brakes lock up: q Turn power down using power knob.
3 If braking was not sufficient: q Turn power up using power knob.
4. Repeat Step (3) until power has been set to a point just below wheel lock up or at a sufficient force as to achieve maximum braking power.
5. Using the brake pedal, make a few low speed stops to check the power setting.
-- Edited by Gundog on Wednesday 10th of August 2022 09:30:17 AM