Need a little help (minor spoiler)

[INeedHelpPlease]

at the end and I need to find 3 pumps, where are they? the map doesn't help, I'm just lost

[door noob]

Use the sewers to go up into the caves, then when your on the ledge to the to go into into Arkham North, use your zip-line to swing across onto the sewage water, climb up, then use the zip-line again when necessary then you'll find a breakable wall with three thugs behind it, use the bat-claw to brake it, and then you'll find your three pumps, remember to use the cryptographic frequencer.