Jump to content

Welcome to TheMalibuCrew!

As a guest, you are welcome to poke around and view the majority of the content that we have to offer, but in order to post, search, contact members, and get full use out of the website you will need to Register for an Account. It's free and it's easy, so don't hesitate to join the TheMalibuCrew Family today!

Sign in to follow this  
pkenney

Sportster Trans vent Hurth

Recommended Posts

pkenney

The vent on my transmission is holding pressure. . It is causing  trans fluid  to  push  out front  seal. When  the boat was brand new I would see a few drops  on engine  cover from rear seal. I LET SOME ONE DRIVE IT LAST WEEKEND . I looked over he was doing 50 mph. Not sure this had anything to do with it. I found a small amount of  trans fluid on bottom of bell housing when wiping down engine.

 

IMG_0329.JPG

Edited by pkenney
Left something out

Share this post


Link to post
MadMan
33 minutes ago, pkenney said:

The vent on my transmission is holding pressure.

Why do you think the vent is holding pressure?

Share this post


Link to post
pkenney
8 hours ago, MadMan said:

Why do you think the vent is holding pressure?

When  I remove dipstick there  is a lot  of pressure. Not just a little, I will screw a nipple with a tee and the vent,.

 In the tee I'm  going to install a gage.

Share this post


Link to post
TCdave

Mine has always held a little pressure, no leaks @658 hours.

Share this post


Link to post
Engine Nut

I bet that the sound you are hearing when you remove the dipstick is actually air going back into the transmission from a partial vacuum that occurs normally in the trans. The vent is actually a check valve that lets air out but not back in. When the trans gets hot the air in the reservoir expands and escapes. When the trans cools, the check valve closes and doesn't let the air come back into the transmission. That's one good reason to make sure your bilge is dry. We occasionally see water get pulled into the transmission past the output shaft seal because of the partial vacuum. The seals are single lip seals designed to keep fluid in but not designed to keep water out.

Share this post


Link to post
pkenney
On 9/3/2016 at 9:28 AM, Engine Nut said:

I bet that the sound you are hearing when you remove the dipstick is actually air going back into the transmission from a partial vacuum that occurs normally in the trans. The vent is actually a check valve that lets air out but not back in. When the trans gets hot the air in the reservoir expands and escapes. When the trans cools, the check valve closes and doesn't let the air come back into the transmission. That's one good reason to make sure your bilge is dry. We occasionally see water get pulled into the transmission past the output shaft seal because of the partial vacuum. The seals are single lip seals designed to keep fluid in but not designed to keep water out.

But there is more pressure when trans. is hot . I am going to put a tee in with vent and pressure gage.

Share this post


Link to post
Engine Nut

There should be no pressure in the transmission. It is possible that the check valve is stuck or there is some debris in the vent. Remove the vent and pry the sheet metal cap off the vent and remove the spring and check disc then put the cap back on. You really don't need the check valve as long as water doesn't get above the level of the vent.

Share this post


Link to post
pkenney
On 9/3/2016 at 9:28 AM, Engine Nut said:

I bet that the sound you are hearing when you remove the dipstick is actually air going back into the transmission from a partial vacuum that occurs normally in the trans. The vent is actually a check valve that lets air out but not back in. When the trans gets hot the air in the reservoir expands and escapes. When the trans cools, the check valve closes and doesn't let the air come back into the transmission. That's one good reason to make sure your bilge is dry. We occasionally see water get pulled into the transmission past the output shaft seal because of the partial vacuum. The seals are single lip seals designed to keep fluid in but not designed to keep water out.

But there is more pressure when trans. is hot . I am going to put a tee in with vent and pressure gage.

Share this post


Link to post
pkenney
10 hours ago, Engine Nut said:

There should be no pressure in the transmission. It is possible that the check valve is stuck or there is some debris in the vent. Remove the vent and pry the sheet metal cap off the vent and remove the spring and check disc then put the cap back on. You really don't need the check valve as long as water doesn't get above the level of the 

Share this post


Link to post
pkenney

Larry, the boat was brand new had small leak from rear seal. I would

 see drops of trans. Fluid on engine cover. I had some warranty  work done. I asked about this problem they changed the vent. I took the vent apart it is a check valve. My thought  was it is made to keep water out.  After I found some trans. Fluid on bell housing 

.. I removed the vent I am able  to blow through  it. The boat has 350 hrs on it. I would  think that  the seal should not be leaking. Do you have any other thoughts  of why I found the fluid? If I have to  remove trans . It looks  like no big deal. Someone  mentioned  a gasket. Thanks for you help. Paul Kenney

10 hours ago, Engine Nut said:

There should be no pressure in the transmission. It is possible that the check valve is stuck or there is some debris in the vent. Remove the vent and pry the sheet metal cap off the vent and remove the spring and check disc then put the cap back on. You really don't need the check valve as long as water doesn't get above the level of the vent.

 

Share this post


Link to post
Engine Nut

It is possible that there is a front seal leak bot before I got too crazy, there are some hex head fasteners on the back side of the shift valve assembly. We sometimes see them loose and when they leak the oil runs down the bell housing and puddles at the bottom making you think you have a seal leak. Make sure those hex head fasteners are tight. Actually, one is a cap for the detent ball/spring and one is a shoulder bolt that keeps the shift valve from coming out.

Share this post


Link to post
pkenney
2 hours ago, Engine Nut said:

It is possible that there is a front seal leak bot before I got too crazy, there are some hex head fasteners on the back side of the shift valve assembly. We sometimes see them loose and when they leak the oil runs down the bell housing and puddles at the bottom making you think you have a seal leak. Make sure those hex head fasteners are tight. Actually, one is a cap for the detent ball/spring and one is a shoulder bolt that keeps the shift valve from coming out.

Thanks I will check.

Share this post


Link to post

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Sign in to follow this  

×
×
  • Create New...