Exhaust break

Moderators: stan, Chris S, Zoltan

User avatar
bromleyxphil
Gold
Posts: 650
Joined: Tue Jun 23, 2015 9:24 am
Location: Bolton
Contact:

Re: Exhaust break

Postby bromleyxphil » Sun Feb 04, 2018 8:06 pm

After reading this from an EB company.

“The exhaust brake which is located below the turbocharger is a valving system that can be partly closed to restrict (but not totally close off) exhaust flow. This valve activates when the driver releases the fuel throttle pedal. Under these conditions, the exhaust flow from the cylinders is bottlenecked and rapidly builds pressure in the exhaust system upstream from the exhaust brake pushing down on the piston, restricting the exhaust flow generate substantial braking. That’s what makes an exhaust brake so effective.

The pressure build up in the exhaust system must be controlled, check with the manufacture of your engine for your specifications. To much restriction can actually damage a diesel engine. If the pressure in the exhaust system, which also pushes against the back side of closed exhaust valves exceeds the valve springs ability to hold the valves on their seats, the exhaust valves would be forced open and the pistons could hit the valves, causing severe engine damage. An exhaust brake must vent some exhaust flow through the exhaust system to keep the peak system pressure below the danger point. This is a carefully engineered setting by manufactures to determination maximum practical braking without causing engine damage. If it weren’t for the potential valve-train or exhaust system rupture problems, the exhaust brake system could be designed to create incredible engine braking force.”

Looks like I need some quite technical detail from MAN.

crinklystarfish
Gold
Posts: 1168
Joined: Mon Jan 30, 2012 9:34 am
Contact:

Re: Exhaust break

Postby crinklystarfish » Wed Feb 07, 2018 1:43 pm

Phil, does any version / variant of your specific MAN model have an exhaust brake fitted as a standard factory item?

User avatar
bromleyxphil
Gold
Posts: 650
Joined: Tue Jun 23, 2015 9:24 am
Location: Bolton
Contact:

Re: Exhaust break

Postby bromleyxphil » Wed Feb 07, 2018 5:52 pm

Hi Steve they must have as it’s operation is listed in the handbook and there is a blanking piece in the exhaust the exact size to fit one in.

Ivan C
Gold
Posts: 316
Joined: Mon Oct 17, 2016 5:38 am

Re: Exhaust break

Postby Ivan C » Wed Feb 07, 2018 6:49 pm

As far as I know it was optional on 7.5T and standard above.
If you want my chassis no. to check if exhaust valves etc. are the same let me know
Ivan C

crinklystarfish
Gold
Posts: 1168
Joined: Mon Jan 30, 2012 9:34 am
Contact:

Re: Exhaust break

Postby crinklystarfish » Thu Feb 08, 2018 9:23 am

Can't be that hard a job then chaps.

If MAN did it from the factory, it should just be a matter of tracking down the spec. It may even be that the exhaust valve springs are already rated suitably to prevent lifting-off-the-seat problems.

It sounds like the whole thing is adjustable anyway so if it's set up just to give a little retardation effect rather than standing the thing on its nose, that would minimise stress on the valves and seals.

At 7.5(ish) tons even a little retardation effect will go a long way.
Last edited by crinklystarfish on Fri Feb 09, 2018 8:20 am, edited 1 time in total.

User avatar
bromleyxphil
Gold
Posts: 650
Joined: Tue Jun 23, 2015 9:24 am
Location: Bolton
Contact:

Re: Exhaust break

Postby bromleyxphil » Thu Feb 08, 2018 5:10 pm

MAN technical have got back to me to say that they have escalated my question to the factory in Germany so hopefully they will come up with the info I need. Watch this space.

User avatar
NeilandPat
Gold
Posts: 1347
Joined: Mon Feb 08, 2010 2:16 pm
Location: Chelmsford UK

Re: Exhaust break

Postby NeilandPat » Sat Feb 17, 2018 1:06 pm

Stick with it Phil.

You are going to need it. I use mine all the time .

Couldn't be without it here

Neil

User avatar
bromleyxphil
Gold
Posts: 650
Joined: Tue Jun 23, 2015 9:24 am
Location: Bolton
Contact:

Re: Exhaust break

Postby bromleyxphil » Mon Mar 12, 2018 12:57 pm

Image
Guys i have found this section from the MAN documentation {I added the blue arrow} it reads to me as, the 6 cylinder engine has EVB and needs a solid flap setting but the 4 cylinder doesn’t and has a 4mm hole drilled through it. The guy at my local MAN says this document refers to engines with EVB and as mine doesn't have EVB its not relevent to me......how do you read it?
Mine is a 4 cylinder.

User avatar
bromleyxphil
Gold
Posts: 650
Joined: Tue Jun 23, 2015 9:24 am
Location: Bolton
Contact:

Re: Exhaust break

Postby bromleyxphil » Mon Mar 12, 2018 4:03 pm

Anyone know what an “air flow sensor flap” is in the context of the above document.

User avatar
bromleyxphil
Gold
Posts: 650
Joined: Tue Jun 23, 2015 9:24 am
Location: Bolton
Contact:

Re: Exhaust break

Postby bromleyxphil » Thu Mar 15, 2018 2:46 pm

well £700 lighter and i have all of the MAN bits
Image
Now just need to find the fittings, hose and be brave enough to put it all on
Image


Return to “Trucks”

Who is online

Users browsing this forum: No registered users and 2 guests

cron