1965 Vert: Bleeding the hydraulic top system

[Live2Ride57]

Hi, I just replaced my hydraulic pump/reservoir and am now trying to bleed air out of the system. I have the top rams disconnected. The issue I see is the passenger side ram moves faster and reaches it limits (in/out) before the other side. Its not really close. I have also noticed that once the passenger side ram reaches its limit the other side wiil speed up and I frequently hear air bubbles bubbles as it reaches its out limit. I'm assuming this ram speed difference is caused by air in the system, but could there also be another reason like weak solenoids or something else? Thanks in advance for your inputs.

[frasern]

This is normal. Hydraulic fluid will always find the path of least resistance, the cylinder closest to the pump has less tubing, so it will move first. Attaching them to their load, equalizes the resistance.
The bubbling may be the pump sucking air near it's limit, this should stop once the cylinders are re-connected, then cycle the top a couple of times, with the fluid topped up, to remove what air is left.

When you live in a farming area, as I do, you pick up a thing or two about hydraulics.

[bd94s10]

Yes, that should be fine as Fraser noted. I wish I had created a video when Blair and Theresa helped me bleed my system on my '64. It is one of my most requested videos on my YouTube Channel: https://www.youtube.com/channel/UC46SrZ ... 2lGJBcvf1w

I changed my solenoids when I did the work on why '64. Please note... On my '64 Blair and Theresa originally threw on another hydro pump. It was working much better. Little did I know but the line running to the ram on the driver side burst. I kept adding fluid as they were bleeding the system. I was like man this is taking way too much. I walked over to look in the car (was looking fro something I think) and noticed a shit ton of fluid under where the rear seat is at. The reason I say this is keep this in mind.. if you replace say the pump and the lines are old... you could blow out a line and then I'd suggest replacing all the lines. That is what snow balled into me replacing everything. Not saying you will need to do this but something to keep in mind especially if you find your adding in a ton of fluid (Type F only as you probably know). I'd suggest maybe even pulling the rear seat if need be to keep and eye on it.

[frasern]

The earlier cars used brake fluid, I'm not sure when that changed, but I'm sure '65 was ATF. When I redo my '62, I will convert to ATF, but Cashman said you must change everything to do this.
As my top has not been used in 4 1/2 decades, it would be foolish NOT to replace everything.

[1966BlackonBlackConv]

I have bled my 66 system many times. I am still not good at it! I am a believer in bleeding the system on the bench first. I don’t know if that is possible on pre 66 models. I also stand the pump vertical when bleeding on the car.

Three words of advice.
1. When the rams are disconnected, do not attempt to run the rams to full extension- you will ruin them the first time it goes all the way out. I know someone who did this (Me).

2. At every stage, allow time for the fluid to clear of micro bubbles in the reservoir. You will hear cavitation especially in the early stages of bleeding. Be patient when bleeding the system with aerated fluid- you’re not making progress if the fluid has micro bubbles in it. The longer you wait the less cavitation in the pump you will get. If you wait you will purge more air from the system. I waited 30 minutes between bleed cycles this afternoon. That seemed to be productive. It also allows time for the motor to cool.

3. When rams are connected, make sure the plug is in tight during the down cycle- or you will have lots of fluid purge from the fill hole, especially in the early stages.

I recently rebuilt my factory pump and motor. I installed it today and it worked fine once I got all the air out. It's back on the bench for detailing paint etc...

[TonyC]

The earlier cars used brake fluid, I'm not sure when that changed, but I'm sure '65 was ATF. When I redo my '62, I will convert to ATF, but Cashman said you must change everything to do this.
As my top has not been used in 4 1/2 decades, it would be foolish NOT to replace everything.

Normally I don't bother chiming in on any 'vert issues, but I do know the history of the fluid change from Ron Baker; so I'll contribute it here. '63 was the last year they employed brake fluid; from '64 to the end they used Type F ATF. According to Baker, and I'm pretty sure other 'vert vets can attest, the earlier systems can be converted to run on ATF. However, that requires an extensive and thorough flushing of every nook and cranny inside the hydraulic system, as brake fluid and ATF don't mix well together, except in a recycle drum.

---Tony

[bd94s10]

Fraser, good point. They did use brake fluid and if your not upgrading everything I can see what you're saying.

To Tony's point above you can (I've been told) upgrade to all ATF but has to be flushed. I'd almost wait until you update everything was updated Live2Ride57 to fill it with ATF but like I said with the new pump you could blow a line like I did and then you will have to buy everything new anyways. Best of luck man!