Using the gears to slow

ricc said:
years ago i had a david brown tractor that had an extra pedal above the rear wheel brake pedals... connected to a butterfly valve in the exit of the exhaust manifold , virtually blocked the exhaust completely to slow the engine down. common practice now to use hydraulic brakes on the trailers cos its much easier to replace trailer brakes than the ones hidden in the tractors transmission.
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Brakes on a old gray fergie were crap.
Yes and we invented the tractor. :)
 
If you wern't meant to use your gears why is there a down hill option on modern vans
 
Some Coaches used to have Telma retarders.
Used juice from the battery and a big magnet to slow the propshaft (I think)
But the wires could overheat again I think.
These days you might harvest the energy to top up batteries.
I believe the Toyota Prius (Hybrid) does exactly that from the footbrake.
 
How would you deal with the situation in an automatic? From a distant memory there was '3rd' gear but I can't remember seeing a first and second option.
 
I always try and approach downwards slopes in as low a speed as practical and then get the MH into 3rd (or 2nd) before too much speed has been built up in order to save the clutch some. I'm not averse to dabbing the brakes then to keep the speed reasonable, that way both the engine and to a lesser extent, the brakes, are taking the strain. Yes the engine whines on the descent but as mentioned, better than having brake fade or worse.

The Ducato has a Hill Descent button, which I have never used as I suspect it applies brakes to keep the speed at around 15Kph rather than relying on the engine. In many instances I find that the set speed it tries to keep to, would be too slow anyway.
 
Lemut said:
How would you deal with the situation in an automatic? From a distant memory there was '3rd' gear but I can't remember seeing a first and second option.
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My van is automatic, if I am going downhill and use the foot brake it changes down then will hold it back on engine breaking. I have auto cars which did the same. That’s not CTX style auto though, not sure what they do as I didn’t like the one I had.
 
Our car is an automatic and has engine braking.

Also does the auto box have an option for manual? I've never had an auto MH but our cars are always auto and you can just push the gear stick to the left for manual control/changing. If so couldn't it just be put into a low gear using that?
 
GMJ said:
Our car is an automatic and has engine braking.

Also does the auto box have an option for manual? I've never had an auto MH but our cars are always auto and you can just push the gear stick to the left for manual control/changing. If so couldn't it just be put into a low gear using that?
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I think all my cars have had semi manual option for at least the last 10 years, the van has the same except when in A (Merc equivalent of drive you just keep pushing stick up or down to change.
 
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When riding around New Zealand in 2000 I remember seeing signs on the approach to towns telling trucks to NOT use exhaust braking in the town.

I was told this was due to the noise levels it created.

Can manufacturers do it quietly now and if so how have they achieved it with lower noise levels?
 
Modern brakes do not fade, rally cars brake very hard and at night the discs glow red hot, change down before a decent and dab brakes to stop over speed, letting an engine rev a bit up to the green band will do no harm, steady and easy gets you to that no overnight parking spot. 😂
 
Exhaust brakes are noisy and work better at higher revs, so additional engine noise too.
Retarders make less noise than exhaust brakes.
 
trevskoda said:
Modern brakes do not fade, rally cars brake very hard and at night the discs glow red hot, change down before a decent and dab brakes to stop over speed, letting an engine rev a bit up to the green band will do no harm, steady and easy gets you to that no overnight parking spot. 😂
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Out of interest - genuine question as I don't know - wouldn't modern rally cars have ceramic brakes which aid braking performance?
 
GMJ said:
Out of interest - genuine question as I don't know - wouldn't modern rally cars have ceramic brakes which aid braking performance?
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Yes, some do, but 20 years back no they did not and many times I saw the red glow as I watched them descend down through the Antrim glens.
 
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Round my way we have a lot of 60's into 30's and I tried engine braking and neither myself, van or car behind me seemed particularly impressed tbh
 
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