Q: Power steering fluid leak on 2008 Honda Civic

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The shop (a dealership) where I usually took my car to told me my car is leaking power steering fluid and gave me an estimate that is just too high. I have doubts about the claim and also from previous experience, I just don't trust their expertise 100%. First I add power steering fluid to full and then check the level in the reservoir every week to see if the level has fallen. The check is done every Saturday morning before the car was started.
I did notice a very slow decrease over the course of about 6 weeks.

Can that be the verification that the power steering fluid is indeed leaking ?

(2) Answers
(3) Comments
What did they say was the cause? pump ,lines, gearbox (rack)? Are you using only HONDA compatible fluid? Other fluids can damage the seals.
Thanks for the reply.

That's the reason I don't quite trust them. They said they don't know the cause and have to take the whole assembly out (probably include the engine) to diagnosis. They give me an estimate of $1500 that's supposed
to cover the cost of labor.

Yes, I have been using only Honda parts.
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