Chicago will hold another police entrance exam in April — and reduce the “pre-employment process” by up to two months — to maintain a continuous pipeline of candidates needed to bolster the police force by 970 officers over the next two years, aldermen were assured Monday.

The opening day of City Council budget hearings focused heavily on Mayor Rahm Emanuel’s ability to deliver his promised police hiring surge.

Year One of the two-year surge calls for the city to fill 495 police vacancies, keep pace with rising retirements and still hire enough police officers in 2017 to add 250 patrol officers, 37 sergeants, 50 lieutenants, 92 field training officers and 100 detectives to raise an abysmal clearance rate for homicides and shootings.

On Monday, the Emanuel administration fleshed out details of the ambitious hiring plan. It includes:

• Holding another police exam in April to “accommodate the anticipated large number” of new hires, with planning and recruitment already underway and an application process opening next month. The city also plans to “repeat and expand successful strategies” used to bolster the number of minority applicants, including eliminating the $30 testing fee, according to documents distributed to aldermen at a budget hearing.

• Reviewing the “entire hiring process from beginning to end” to reduce the six-month timetable for processing and screening applicants by up to two months.

The largest drop-off rate occurs during the run-up to the so-called POWER physical fitness test. To reverse that trend, text messages will be sent to candidates to remind them of the date and time of pre-POWER exams.

For the first time, candidates who fail the pre-POWER test administered by the Chicago Police Department will be allowed to retake the test. Those who have passed within the last year will not be required to retake the test.

Candidates who either don’t pass the pre-POWER test or cannot make the assigned date will be allowed to take the test at a state-approved facility and submit proof.

“We tend to lose about 50 percent of the applicants at that pre-POWER stage,” city budget director Alex Holt said Monday. “So they’re looking to make some changes to up the number of people who make it through the pre-POWER test so we have a bigger pool of candidates going forward and heading into the academy. It makes it easier for them to increase the numbers for next year.”

• Identifying “temporary auxiliary spaces” to train veteran officers in de-escalation tactics, a new use-of-force policy and crisis intervention to serve people with mental health issues. The temporary training facilities, first disclosed by the Chicago Sun-Times, would also be used for “promotional training above the rank of police officer.”

That would leave the cramped and antiquated police academy at 1300 W. Jackson, which Emanuel ultimately intends to replace, to be converted into a factory for new officers.

• Having two new classes enter the police academy by the end of 2016 — one starting at the end of this month, the other in December. That would be followed by classes of 100 recruit per month beginning in January and continuing for 11 of the 12 months next year.

• Filling all vacancies in the ranks of field training officer in January and February, then proceeding to fill the 92 new FTO positions.

• Hiring enough detectives to fill existing vacancies by March, followed by a second class of 100 new detectives by April. Lieutenant vacancies will be filled by March.

• Establishing a June 2017 deadline to fill vacancies in the all-important rank of sergeant; add the 37 new sergeants; and fill any additional openings created by promotions to the rank of lieutenants filled by June.

The Chicago Sun-Times reported on Sunday that, lured by the expiring offer of free health insurance at age 55, 274 Chicago Police officers have declared their intention to retire by June 30, making it more difficult for Emanuel to deliver on his two-year promise.

Coupled with the 495 vacancies across all ranks, that means Emanuel will begin the job of delivering on his promised police hiring surge 769 officers in the hole.

On Monday, Holt assured aldermen that she has taken all of those numbers into account in a budget that includes: $40 million for salary and benefits for the 545 new sworn positions; $8 million for the “pre-employment” process that includes background checks and drug testing; $2 million for equipment and supplies; and $3.2 million for curriculum development and training.

The mayor’s budget also includes four new positions in the Department of Human Resources to assist in the police hiring surge and two positions to bolster diversity in the workforce with a particular focus on police.

“Our hiring plan for 2017 assumes that we’re gonna need to fill approximately 1,000 to 1,100 police officer vacancies — which are the new ones, the attrition we’re planning for and the promotional attrition. We’re assuming that all of that will be hired and filled over the course of next year,” Holt said.

“One thing we’ve done in the budget is to substantially increase the amount of money that’s available for pre-employment,” she said. “If we’re gonna be screening and hiring this many recruits, we need additional funding.”

Despite the details and assurances provided Monday, Ald. Anthony Beale (9th), former longtime chairman of the City Council’s Police Committee, still has his doubts about the mayor’s ability to pull off the police hiring surge desperately needed to stop a 50 percent surge in homicides and shootings.

“I have a real concern that it’s going to be very difficult to keep up with retirements and everything. Unless we add more capacity to the actual training academy, I don’t think we’ will get to the number in the time that we need to get there,” Beale said.

“It’s a very aggressive goal. I hope we get there,” he said. “But I don’t think we can with the capacity we have.”

Last year, an unprecedented outreach campaign to diversify the Chicago Police Department attracted 14,200 applicants for an April 16 police exam. Of those, 29 percent were African-American and 39 percent were Hispanic.

The 71 percent minority showing was a 13 percent improvement from the previous outreach campaign.

Last year’s police exam was the second in two years. Next year’s test will be the third in four years.