Handbrake active but no lights?

[xXCARL1992Xx]

i only know that on Scania they dont go on

in on of Squirrels video where he drove on Scania he asked if the break light goes on with the retarder, the instructor said they dont

[Nielsen_]

Alright thanks guys, and as Reef said my brake light also activate when using my retarder brake

[Reef]

Exhaust brakes on all the trucks I drove irl the brakelights didn't come on, I think that retarders do have the lights come on with most modern trucks but this I cannot confirm as none of the trucks I'd driven had retarders at the time. Also never drove a truck with an engine or jake brake either (these things aren't really that common on fleet spec trucks in the UK.)

[xXCARL1992Xx]

https://youtu.be/IdmBtMxNOQI?t=994

here is the part where he askes and the instructor answered

[natvander]

It may be country specific - down here brake lights activate when engine / jake / retarder brakes are applied (including our Scanias). Which to me makes sense as you are applying brakes and potentially slowing down your vehicle.

[Reef]

The exhaust brake will never really slow you down that much, it's function is to try and help you maintain a speed (avoid overrun) on a gradual prolonged descent without having to continually use your service brakes (foot pedal) and thus risking overheating and brake fade (that's really scary, trust me!) so like I said previously they didn't on any truck I'd driven at the time which included DAF CF85's, older Renault Premiums, MB Actros MP1 and 2's, Scania series 3, 4 and 5's, Volvo FH12 mk1 and 2's, activate the brake lights.

Retarders and engine/jake brakes are completely different animals and are a lot more forceful and will (on higher settings at least as most are adjustable) slow you quite noticeably, that I assume is why they then activate the lights.

Like I say I can't claim expertise on the latter types as I've never had the opportunity to use them, so you'll have to forgive and correct any irregularities in my comment.

On a quick search about I found this brief explanation of the different types, 'I'm assuming' it's correct about exhaust and engine braking but cannot confirm the legitimacy of the retarder as I don't know much about them.

the term retarder refers to an electromagnetic device within the transmission which magnetically puts drag on the transmission. This device is used on trucks, busses and could be used on RV's but is seldom found on any but the most expensive RV's.

An engine brake is accomplished by changing the timing of the valves so that the exhaust valve is closed when it would normally open. This causes the piston to compress the air within the engine cylinder. Since the cylinder is tightly sealed, this is a very effective way to slow the vehicle. Some engine brakes have several levels applying the breaking to three or six cylinders to accomplish different braking power as needed.

An exhaust brake impedes the flow of the exhaust from the engine in the exhaust pipe. Since the exhaust pipe seal isn't as positive as the seal in the cylinders in the engine, this brake is somewhat less effective.

(coloured text was an edit to clarify what I meant, I initially wrote 'I know', that however is not accurate, 'I assume', is)

[xXCARL1992Xx]

electromagnetic retarder ?

i only know of the hydraulic ones where the transmission is pumping oil and if you set it higher it pumps more oil and produces more drag in the transmission to slow you down

or like this

Watch on YouTube

[Reef]

Ahh yes, I did see references to hydraulic retarders but didn't look any further into it, interesting, so there are apparently more than one type of retarder then it would seem, tbh I'd imagine the hydraulic oil type being the more common type thinking about it.

[xXCARL1992Xx]

we had one Actros transmission at work there was a hydraulic one that you could see from the outside

[natvander]

Retarders will certainly slow the truck down. Seat belt use in our job became much more common with our previous trucks as you felt like you were about to be launched through the windscreen when the retarder was activated. The following video (at around the 2:00 mark) has the presenter stating that, using a combination of retarder and engine brake he rarely used the foot brake on a Scania grossing over 100t.
https://www.youtube.com/watch?v=D8eI4D9wDC4

Interesting fact - DAFs actually have 'Jake' brakes, just not the noisy brakes normally associated with the name - http://www.jacobsvehiclesystems.com/customers/daf/