Hello... I've rented a Bosch 11318 Hammer drill and it did not come with a manual......could you please tell me how to insert the bit. thank you.

Not all bits for hammer drills are the same as the slots in the sides of the shanks are different between makes . There is a standard between hilti and ramset drill bits but other makers have different ideas Check out the shanks of your drill bits and look for the slot that holds in the bit.

Have you removed the 4 gearbox screws? the cover should lift off. sometimes if a brush holder has over heated then the two halves get stuck together in places.

Hi, have you tried the various positions on the front part of the gearbox behind the 'chuck'?
If so, then Im afraid it must go in for repair. These are not an easy fix and personally I would recommend you ask for a 'quotation' as it could be just something simple to do with the 'Gearbox' selector, but it could also be something a lot more serious within the Gearbox.
Good Luck & Best Wishes, John..

SAME ISSUE *****SOLVED*****

You were on the right track but needed to go farther with top description without disassembly!!

I have a barely used Hammer drill also that will rotate and run motor but does not hammer in any position.

Grease is the issue.....

Heat and sitting causes the grease to weep out & even a small amount of dust binds up the hammer drill.

******SOLUTION*****

GREASE, GREASE & MORE GREASE....

REMOVE BIT....SQUIRT IN ALOT OF THE BOSCH GREASE HOLD LOCKING CHUCK OPEN. INSERT A SPLINED BIT INTO THE HOLE AND PLUNGE GREASE IN SLOWLY SEVERAL TIMES. REMOVE BIT & REFILL GREASE & REPEAT.....VOILA.....HAMMER WORKING AGAIN....

BE SURE TO USE LOTS OF GREASE & DUST COVERS ON Bosch HD WHEN WORKING. WE ALL ERROR AND FAIL TO MAINTAIN FROM TIME TO TIME!

If the bits get a bit distorted they will stick, if you have a bench vise clamp the bit in the jaws and give the trigger a quick pull.(reverse) That should dislodge the bit. This happens quite often on lesser quality bits that are made of soft metal.

some drill bits have a certain way to be installed,if not put in correctly it will loosten up

You might have oil escaping past the ram seal. Other than grease for the chuck you should not have anything getting on your bits. I would have it checked out since it is so new.

Hello. Wrap a towel around the chuck and use a pipe wrench or a pair of channel locks to put a little force on the chuck. J.

Hello. If the gun has cooled down and still will not start up then the gun will have to go into a Bosch service center for a repair. Here is the owner manual with the pertinent info

http://mdm.boschwebservices.com/MDMCache/English%20[US]/t10/0000000/r00018v-1.pdf

please rate my answer as very helpful. thanks.. Joe

This site does not have the manual for the exact model number you are seeking but several that are similar and may be helpful:
http://powertool.manualsonline.com/ex/thread/view/idThread/76898