Forums
New posts
Search forums
What's new
New posts
New media
New media comments
New profile posts
Latest activity
Media
New media
New comments
Search media
Members
Current visitors
New profile posts
Search profile posts
Log in
Register
What's new
Search
Search
Search titles and first posts only
Search titles only
By:
New posts
Search forums
Menu
Log in
Register
Install the app
Install
Forums
Bobcat Skidsteer Forums
General Bobcat Skidsteer Forum
453F Air in Hydraulic system
JavaScript is disabled. For a better experience, please enable JavaScript in your browser before proceeding.
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an
alternative browser
.
Reply to thread
Help Support SkidSteer Forum:
Message
<blockquote data-quote="Tazza" data-source="post: 3036" data-attributes="member: 82"><p>I really can't see how air could enter the system if the oil level is correct and there are no leaks. Did it just start having this problem? or has it been doing it for a long time?</p><p>I have noticed purging the air from my 743 has taken quite a long time and its still not rite. I had the lift arms working well, but when i attached the tilt cylinder i now have air back in my lift arms. Could it simply be air traped in the system that will eventually bleed out?</p><p>Can you give me a bit more info on the history of the problem?</p><p>The hydraulic circuitry is a closed loop with the reserve above the pump, there is no way i can see for air to be drawn in. No hoses run at a negative pressure to draw air in, they are all at charge pressure or higher (except the hose to the reserve tank that just has gravety against it).</p><p>There has to be an answer, as there are 2 people on this forum alone that have this problem, surly there will be more around.</p><p>One thought, the only other thing i could think of is bad ram seals. All the rams are double acting, this means you need constant pressure against the pressure seal for it to seal against the rod. If you have a load on the ram and move the spool when the engine is off, i guess there is a chance it could draw in air (still very low i would guess) as the rod retracts causing a low pressure at the seal and sucking in air?? Its just a thought.</p></blockquote><p></p>
[QUOTE="Tazza, post: 3036, member: 82"] I really can't see how air could enter the system if the oil level is correct and there are no leaks. Did it just start having this problem? or has it been doing it for a long time? I have noticed purging the air from my 743 has taken quite a long time and its still not rite. I had the lift arms working well, but when i attached the tilt cylinder i now have air back in my lift arms. Could it simply be air traped in the system that will eventually bleed out? Can you give me a bit more info on the history of the problem? The hydraulic circuitry is a closed loop with the reserve above the pump, there is no way i can see for air to be drawn in. No hoses run at a negative pressure to draw air in, they are all at charge pressure or higher (except the hose to the reserve tank that just has gravety against it). There has to be an answer, as there are 2 people on this forum alone that have this problem, surly there will be more around. One thought, the only other thing i could think of is bad ram seals. All the rams are double acting, this means you need constant pressure against the pressure seal for it to seal against the rod. If you have a load on the ram and move the spool when the engine is off, i guess there is a chance it could draw in air (still very low i would guess) as the rod retracts causing a low pressure at the seal and sucking in air?? Its just a thought. [/QUOTE]
Verification
Post reply
Forums
Bobcat Skidsteer Forums
General Bobcat Skidsteer Forum
453F Air in Hydraulic system
Top