Adding fluid to convertible's reservoir (1970 300)

[Kaim]

Hi there, I want to change hydraulic fluid to my 300 folding top pump and reservoir assembly. Is that bolt is right to filling (see picture)?
Can I empty the system by disconnecting the hose from the cylinder and emptying the reservoir by using the system's pump?

 

[rags]

yes and yes. the leaking cylinders in my '69 would self empty the reservoir every time i attempted to put the top up.

 

[polaratherapy]

Do you need to prime the system when refilling?

 

[Ripinator]

Do you need to prime the system when refilling?

When I replaced the pistons on my '66 convertible, I emptied the reservoir / pump and refilled it with Dexron II (I think). Afterward, I just put the top up and down a few times, and it pretty much bled itself:

 

[rags]

Do you need to prime the system when refilling?

no. up and down a few times and it will self bleed. the lines are clear and you can watch the air move. i pulled the pump from it's mount and stood it straight up. topped it off as the system was filling. the other thing i did was wire in a plow pump solenoid to the up circuit. power comes directly from the battery.

 

[CBODY67]

In order to avoid "messes", check/adjust the fluid level with the top down (I believe, as that's when the cylinders will be most empty, with more oil in the reservoir)? Check the FSM for verification.

Also be advised that the fluid currently in the system could well be brake fluid, as that was what the OEMs used in the '60s and such, so take appropriate measures to prevent paint damage from the old fluid, just to be safe.

Enjoy!
CBODY67

 

[rags]

(I believe, as that's when the cylinders will be most empty, with more oil in the reservoir)?

power up and down. when one end of the piston empties, the other fills. net fluid level change: zero

 

[PurpleBeeper]

The factory used "Type A" transmission fluid which hasn't been available in many, many years. I'm not sure, but it might have been whale oil (?). As mentioned, unbolt pump & tilt up, fill, cap off, cycle top up/down, top off again if necessary.
Also, dextron/mercon (red) will work just fine. I don't recommend DOT 3 brake fluid because it strips paint like crazy

 

[rags]

Also, dextron/mercon (red) will work just fine

that's what i put in mine twenty plus years ago. nooo brake fluid!

 

[Kaim]

I add ATF Dexron II fluid. I don't think the type of fluid is critical because of simple hydraulic system

 

[CBODY67]

No question that atf is better than brake fluid, but I know that GM still used brake fluid (from Buick FSM info) in 1968, which surprised me. Even recommended using a shop towel soaked in brake fluid to wipe down the cylinder rams, too. Further research indicated that Chrysler was still using brake fluid in those years, too. Just what my research uncovered. And brake fluid had been used well before that, too.

I made my comments as a caution, more than anything else, to make sure that no paint damage happened draining/extracting the old 'unknown" fluid.

To me, using some sort of hydraulic oil would have been best, all things considered. But the normal gas station back then would not have had "hydraulic fluid" in stock for sale, much less any specs for such fluid (other than viscosity). Some stations might not have had atf for sale, either. But every gas station would have brake fluid on hand.

Whatever works,
CBODY67

 

[66l78rat]

Ive always used floor jack hydraulic oil

 

[rkrochen]

I had brake fluid in mine and topped it off with the same. I just didn’t want to mix fluids. Also I believe it called for brake fluid in the FSM. Having said that I would have preferred some sort tranny fluid or even power steering oil.

 

[Big_John]

From the 1970 Chrysler FSM. Section 23-68

"RESERVOIR
Do not add fluid to reservoir until it is installed
in its normal position in the vehicle. Adding fluid to
the reservoir in a position other than its normal
installed position does not allow for fluid expansion
and damage to the reservoir may result.
Measure fluid level only when top is lowered. After
filling reservoir, raise and lower top several times to
expel air that may be trapped in system.
Insufficient fluid in the system may cause slow
raising or noise in the pump or motor. Measure fluid
level and if low, look for a leak due to a broken line
or a loose connection. F i l l reservoir (use only A Q - A TF
Suffix " A " "Dexron" type transmission fluid) until
fluid runs out of f i l l e r hole."

 

[rags]

Do not add fluid to reservoir until it is installed
in its normal position in the vehicle.

no matter how hard i tried, i could not get the fluid to pour horizontally. i could pour it vertically though. stand the pump up, fill it, set it back level and let the excess pour back out into a catch pan. can't argue with success.

 

[Big_John]

no matter how hard i tried, i could not get the fluid to pour horizontally. i could pour it vertically though. stand the pump up, fill it, set it back level and let the excess pour back out into a catch pan. can't argue with success.

Maybe a small funnel with a hose on it... I dunno... Never had to fill one.

But I would say that your way works (and makes sense) as long as you don't overfill.

 

[rags]

Maybe a small funnel with a hose on it.

i tried that. rubber hose fit tight to the fill hole. imagine the air bubbles burping back out through the hose and funnel. more fluid went on the floor than in the reservoir. pump was all ready loose so it was just logical to fill it directly. no offense, but i never owned or had access to a service manual so i always just did what made sense. thankfully, i have some of that.

 

[MrMoparCHP]

I found that a bottle like this worked well for filling the reservoir.

Alan

 

[SPF Required]

I used a small reusable picnic style condiment bottle (think squeezy plastic with a spout) then pushed on a short piece of tubing. Filled that with ATF to fill the reservoir horizontally. Ran the top up and down as instructed and would top off as needed until there were no more bubbles. The reservoir is full when it just barely drips out of the fill port. Top goes up and down great now…. And fast.

 

[rkrochen]

Use a large syringe like you use for basting food.