Is there a filter here

[Already Gone]

Is there a filter of some kind that need to be changed in this hose which goes form the pass side valve cover to the air cleaner of my 72 with 350?

[Davidf]

The filter should be in the air cleaner can. Should look something like this: http://www.amazon.com/WIX-Filters-46990-Breather-F...

[Already Gone]

Originally Posted by Davidf

The filter should be in the air cleaner can. Should look something like this: http://www.amazon.com/WIX-Filters-46...reather+Filter

Thanks

[Wrenchbender Ret]

There is a screen in there that can be cleaned out.

[FirstOwner69]

No filter was used in the air cleaner or attached to the hose. What you see in your picture at the valve cover is referred to in the manuals as a flame arrestor. As Wrenchbender noted, there is a screen that can be cleaned. The filters were used in later model trucks.

[mike16]

i'd like tp see the screen. my 72 c10 came with a filter up at the air cleaner housing. if you donthave the screen, they are available from vette parts vendors

[FirstOwner69]

Originally Posted by mike16

i'd like tp see the screen. my 72 c10 came with a filter up at the air cleaner housing. if you donthave the screen, they are available from vette parts vendors

As I mentioned above, based on my 69, without emissions other than PCV and this breather tube, there is no filter in the original air cleaner for the breather tube. The flow through the breather tube is into the air cleaner and is, therefore, filtered by the air filter itself. Perhaps there is a filter when a smog pump or other emissions equipment is present and also plumbed into the air cleaner housing. The screen I referenced is an integral part of the flame arrestor and not removable.

[Already Gone]

Originally Posted by FirstOwner69

As I mentioned above, based on my 69, without emissions other than PCV and this breather tube, there is no filter in the original air cleaner for the breather tube. The flow through the breather tube is into the air cleaner and is, therefore, filtered by the air filter itself. Perhaps there is a filter when a smog pump or other emissions equipment is present and also plumbed into the air cleaner housing. The screen I referenced is an integral part of the flame arrestor and not removable.

Can you get new flame arrestors as I'm thinking the screen must get a little plugged after 80,000 miles?

[Andy4639]

You need to check the PVC valve and make sure it's not clogged up if it has one installed. Some people install them even if they aren't required. Check it and make sure it's working.

[Already Gone]

Originally Posted by Andy4639

You need to check the PVC valve and make sure it's not clogged up if it has one installed. Some people install them even if they aren't required. Check it and make sure it's working.

I am planning on replacing it as well. Isn't the PCV Valve on the drivers side valve cover?

[SS Tim]

Yes the PCV is in your driver's side valve cover. There were a number of different schemes for ventilation depending on year, series and emissions like EEC.

RTFM... Take a look at the 72 chassis service manual pg 0-9 for specific service and interval.

[snipescastle2]

I have one that I am not going to use, I can send it to you if you like.
Ben

[Already Gone]

Originally Posted by snipescastle2

I have one that I am not going to use, I can send it to you if you like.
Ben

Thank you very much for the offer but I can get most things very reasonably priced from Rock Auto..

[FirstOwner69]

Here are a series of excerpts from Section 6T "Exhaust Emissions Control Systems" of the 1969 GMC Service Manual that describe the operation and care of the flame arrestor. Most of the excerpts are taken from within paragraphs describing all parts of the emission systems.

This manual can be accessed in the link above in SS Tim's post (#11).



CRANKCASE VENTILATION SYSTEMS
DESCRIPTION
All engines are equipped with closed positive
type crankcase ventilation systems. However, the
system design varies from model to model (figs.
1 and 2). Fumes and vapors which would contaminate
the atmosphere are evacuated from the crankcase
and valve compartment(s) through ventilation
valves (figs. 3 and 4). These valves regulate the
flow of gases into intake valve ports in cylinder
head or intake manifold, where they mix with fuel
mixture from carburetor and are burned up in the
combustion chamber. Fresh clean air enters engine
through air cleaner and passes through hose
to rocker arm covers; it then circulates throughout
engine and is finally drawn out through vacuum
check valves and into intake valve ports. Flame
arresters are provided in the system to prevent
any backfire from air cleaner to engine internal
compartment.
It is extremely important that the system is
functioning properly or serious side effects could
occur, such as poor engine idle, excessive sludge
or contaminants in oil, or excessive oil consumption.

IN-LINE 6 AND V8 ENGINES (Fig. 2)
A flame arrester is installed in right
rocker arm cover on V- 8 engines and in hose between
rocker arm cover and air cleaner on Inline
engines.

INSPECTION AND MAINTENANCE
Flame arresters should be washed
in solvent and pressure air dried if not excessively
plugged. A badly plugged arrester should be discarded
and replaced with new unit.
In some cases where breathers are partially
plugged with carbon, it may be possible to clean breather by applying heat from blow torch, etc. If
this is done air pressure should be used to blow
out excess carbon ash when completed.


UNIT REPLACEMENT
FLAME ARRESTERS
1. Loosen hose clamps and remove hoses
from ends of arrester, remove arrester.
2. Install hoses to ends of new or cleaned
arrester, position hose clamps and tighten making
certain hoses are on arrester fitting completely.

[Already Gone]

Originally Posted by FirstOwner69

Here are a series of excerpts from Section 6T "Exhaust Emissions Control Systems" of the 1969 GMC Service Manual that describe the operation and care of the flame arrestor. Most of the excerpts are taken from within paragraphs describing all parts of the emission systems.

This manual can be accessed in the link above in SS Tim's post (#11).



CRANKCASE VENTILATION SYSTEMS
DESCRIPTION
All engines are equipped with closed positive
type crankcase ventilation systems. However, the
system design varies from model to model (figs.
1 and 2). Fumes and vapors which would contaminate
the atmosphere are evacuated from the crankcase
and valve compartment(s) through ventilation
valves (figs. 3 and 4). These valves regulate the
flow of gases into intake valve ports in cylinder
head or intake manifold, where they mix with fuel
mixture from carburetor and are burned up in the
combustion chamber. Fresh clean air enters engine
through air cleaner and passes through hose
to rocker arm covers; it then circulates throughout
engine and is finally drawn out through vacuum
check valves and into intake valve ports. Flame
arresters are provided in the system to prevent
any backfire from air cleaner to engine internal
compartment.
It is extremely important that the system is
functioning properly or serious side effects could
occur, such as poor engine idle, excessive sludge
or contaminants in oil, or excessive oil consumption.

IN-LINE 6 AND V8 ENGINES (Fig. 2)
A flame arrester is installed in right
rocker arm cover on V- 8 engines and in hose between
rocker arm cover and air cleaner on Inline
engines.

INSPECTION AND MAINTENANCE
Flame arresters should be washed
in solvent and pressure air dried if not excessively
plugged. A badly plugged arrester should be discarded
and replaced with new unit.
In some cases where breathers are partially
plugged with carbon, it may be possible to clean breather by applying heat from blow torch, etc. If
this is done air pressure should be used to blow
out excess carbon ash when completed.


UNIT REPLACEMENT
FLAME ARRESTERS
1. Loosen hose clamps and remove hoses
from ends of arrester, remove arrester.
2. Install hoses to ends of new or cleaned
arrester, position hose clamps and tighten making
certain hoses are on arrester fitting completely.

Thanks for the info. I think I'll just change the Flame Arrestor is I can find one.